Please answer the following question: Information: - Pittsburgh is a city in the Commonwealth of Pennsylvania in the United States, and is the county seat of Allegheny County. The Combined Statistical Area (CSA) population of 2,659,937 is the largest in both the Ohio Valley and Appalachia, the second-largest in Pennsylvania after Philadelphia and the 20th-largest in the U.S. Located at the confluence of the Allegheny and Monongahela rivers, which form the Ohio River, Pittsburgh is known as both "the Steel City" for its more than 300 steel-related businesses, and as the "City of Bridges" for its 446 bridges. The city features 30 skyscrapers, two inclines, a pre-revolutionary fortification and the Point State Park at the confluence of the rivers. The city developed as a vital link of the Atlantic coast and Midwest. The mineral-rich Allegheny Mountains made the area coveted by the French and British empires, Virginia, Whiskey Rebels, and Civil War raiders. - CSX Transportation is a Class I railroad in the United States. The main subsidiary of the CSX Corporation, the railroad is headquartered in Jacksonville, Florida, and owns about 21,000 route miles (34,000km). CSX operates one of the three Class I railroads serving most of the East Coast, the other two being the Norfolk Southern Railway (NS) and Canadian Pacific Railway. It also serves the Canadian provinces of Ontario and Quebec. Together CSX and Norfolk Southern Railway have a duopoly over all east-west freight rail traffic east of the Mississippi River. As of October 1, 2014, CSX's total public stock value was slightly over $32billion. - Washington, D.C., formally the District of Columbia and commonly referred to as "Washington", "the District", or simply "D.C.", is the capital of the United States. - Parkersburg is a city in and the county seat of Wood County, West Virginia, United States. Located at the confluence of the Ohio and Little Kanawha rivers, it is the state's third-largest city and the largest city in the ParkersburgMariettaVienna Metropolitan Statistical Area. The population was 31,492 at the 2010 census. Its peak of population was more than 44,000 in 1960. The city is about 14 miles south of Marietta, Ohio. - The Capital Subdivision is a railroad line owned and operated by CSX Transportation in the U.S. state of Maryland and the District of Columbia. The line runs from near Baltimore, Maryland southwest to Washington, D.C. along the former Baltimore and Ohio Rail Road (B&O) Washington Branch. The subdivision's Alexandria Extension provides a connection to Virginia and points south. - A common carrier in common law countries (corresponding to a public carrier in civil law systems, usually called simply a carrier) is a person or company that transports goods or people for any person or company and that is responsible for any possible loss of the goods during transport. A common carrier offers its services to the general public under license or authority provided by a regulatory body. The regulatory body has usually been granted "ministerial authority" by the legislation that created it. The regulatory body may create, interpret, and enforce its regulations upon the common carrier (subject to judicial review) with independence and finality, as long as it acts within the bounds of the enabling legislation. - Oriole Park at Camden Yards, often referred to simply as Camden Yards or Oriole Park, is a Major League Baseball (MLB) ballpark located in Baltimore, Maryland. Home to the Baltimore Orioles, it is the first of the "retro" major league ballparks constructed during the 1990s and early 2000s, and remains one of the most highly praised. It was completed in 1992 to replace Memorial Stadium. - Martinsburg is a city in and the county seat of Berkeley County, West Virginia, USA, in the state's Eastern Panhandle region. Its population was 17,227 at the 2010 census, making it the largest city in the Eastern Panhandle and the ninth largest municipality in the state. Martinsburg is one of the core cities in the Hagerstown-Martinsburg, MD-WV Metropolitan Statistical Area. - The Baltimore Terminal Subdivision is a railroad line owned and operated by CSX Transportation in the U.S. state of Maryland. The line runs from Baltimore to Halethorpe along the original Baltimore and Ohio Railroad (B&O) line, one of the oldest rail lines in the United States and the first passenger railroad line. At its east (north) end, it connects with the Philadelphia Subdivision; its west (south) end has a junction with the Capital Subdivision and the Old Main Line Subdivision. - The Potomac River is located along the mid-Atlantic Ocean coast of the United States and flows into the Chesapeake Bay. The river (main stem and North Branch) is approximately long, with a drainage area of about 14,700 square miles (38,000km). In terms of area, this makes the Potomac River the fourth largest river along the Atlantic coast of the United States and the 21st largest in the United States. Over 5 million people live within the Potomac watershed. - Maryland is a state located in the Mid-Atlantic region of the United States, bordering Virginia, West Virginia, and Washington, D.C. to its south and west; Pennsylvania to its north; and Delaware to its east. The state's largest city is Baltimore, and its capital is Annapolis. Among its occasional nicknames are "Old Line State", the "Free State", and the "Chesapeake Bay State". The state is named after Henrietta Maria of France, the wife of Charles I of England. - The Cumberland Subdivision is a railroad line owned and operated by CSX Transportation in the U.S. states of Maryland and West Virginia. The line runs from Weverton, Maryland west to near Cumberland, Maryland along the old Baltimore and Ohio Rail Road (B&O) main line. At its east end, the Cumberland Subdivision becomes the Metropolitan Subdivision; at its west end (at Mexico, Maryland) it becomes the Cumberland Terminal Subdivision. It meets the Shenandoah Subdivision at Harpers Ferry, West Virginia and the Lurgan Subdivision at Cherry Run, West Virginia. - Philadelphia is the largest city in the Commonwealth of Pennsylvania and the fifth-most populous city in the United States, with an estimated population of 1,567,442 and more than 6million in the seventh-largest metropolitan statistical area, . Philadelphia is the economic and cultural anchor of the Delaware Valleya region located in the Northeastern United States at the confluence of the Delaware and Schuylkill rivers with 7.2million people residing in the eighth-largest combined statistical area in the United States. - The Philadelphia Subdivision is a railroad line owned and operated by CSX Transportation in the U.S. states of Pennsylvania, Delaware, and Maryland. The line runs from Philadelphia, Pennsylvania southwest to Baltimore, Maryland along a former Baltimore and Ohio Railroad (B&O) line. - Pennsylvania (Pennsylvania German: "Pennsylvaani"), officially the Commonwealth of Pennsylvania, is a state located in the northeastern and Mid-Atlantic regions of the United States. The Appalachian Mountains run through its middle. The commonwealth borders Delaware to the southeast, Maryland to the south, West Virginia to the southwest, Ohio to the west, Lake Erie and the Canadian province of Ontario to the northwest, New York to the north, and New Jersey to the east. - The Maryland Transit Administration (MTA) is a state-operated mass transit administration in Maryland, and is part of the Maryland Department of Transportation. It is better known as MTA Maryland to avoid confusion with other cities' transit agencies who share the initials MTA. The MTA operates a comprehensive transit system throughout the Baltimore-Washington Metropolitan Area. There are 80 bus lines serving Baltimore's public transportation needs, along with other services that include the Light Rail, Metro Subway, and MARC Train. With nearly half the population of Baltimore residents lacking access to a car, the MTA is an important part of the regional transit picture. The system has many connections to other transit agencies of Central Maryland, Washington, D.C., Northern Virginia, and south-central Pennsylvania (Hanover, Harrisburg, and York): WMATA, Charm City Circulator, Regional Transportation Agency of Central Maryland, Annapolis Transit, Rabbit Transit, Ride-On, and TransIT. - The Camden Line is a MARC commuter rail line that runs between Union Station , Washington , D.C. , and Camden Station , Baltimore , Maryland , over the CSX Capital Subdivision , and Baltimore Terminal Subdivision . Service began along this route in 1835 as part of the Baltimore and Ohio Railroad ( B&O ) , making it one of the oldest passenger rail lines in the U.S. still in operation . The Camden Line is the shortest MARC line and along with the Brunswick Line , is the successor to the B&O commuter services . - The Ohio River, which streams westward from Pittsburgh, Pennsylvania, to Cairo, Illinois, is the largest tributary, by volume, of the Mississippi River in the United States. At the confluence, the Ohio is considerably bigger than the Mississippi (Ohio at Cairo: 281,500cuft/s (7,960m/s); Mississippi at Thebes: 208,200cuft/s (5,897m/s)) and, thus, is hydrologically the main stream of the whole river system, including the Allegheny River further upstream. - Frederick is a city and the county seat of Frederick County in the U.S. state of Maryland. It is part of the BaltimoreWashington Metropolitan Area. Frederick has been an important crossroads community since it was located in colonial times at the intersection of an important northsouth Indian trail, and eastwest routes to the Chesapeake Bay both at Baltimore and what became Washington, D.C. and across the Appalachian mountains to the Ohio River watershed. It is a part of the Washington-Arlington-Alexandria, DC-VA-MD-WV Metropolitan Statistical Area, which is part of a greater Washington-Baltimore-Arlington, DC-MD-VA-WV-PA Combined Statistical Area. The city's population was 65,239 people at the 2010 United States Census, making it the second-largest incorporated city in Maryland, behind Baltimore. - Bombardier Transportation is the rail equipment division of the Canadian firm Bombardier Inc. Bombardier Transportation is one of the world's largest companies in the rail vehicle and equipment manufacturing and servicing industry. The division is headquartered in Berlin, Germany, and has regional offices and major development facilities in Canada (Montreal and Toronto) and the United States (Plattsburgh, New York). Bombardier Transportation has many minor production and development facilities worldwide. - Virginia (, officially the Commonwealth of Virginia) is a state located in the Mid-Atlantic region of the United States, as well as in the historic Southeast. Virginia is nicknamed the "Old Dominion" due to its status as the first colonial possession established in mainland British America, and "Mother of Presidents" because eight U.S. presidents were born there, more than any other state. The geography and climate of the Commonwealth are shaped by the Blue Ridge Mountains and the Chesapeake Bay, which provide habitat for much of its flora and fauna. The capital of the Commonwealth is Richmond; Virginia Beach is the most populous city, and Fairfax County is the most populous political subdivision. The Commonwealth's estimated population is over 8.3 million, which is slightly less than New York City. - The Erie Canal is a canal in New York that is part of the eastwest, cross-state route of the New York State Canal System (formerly known as the New York State Barge Canal). Originally, it runs about from Albany, on the Hudson River, to Buffalo, at Lake Erie. It was built to create a navigable water route from New York City and the Atlantic Ocean to the Great Lakes. - Commuter rail, also called suburban rail, is a passenger rail transport service that primarily operates between a city centre, and the middle to outer suburbs beyond 15km (10 miles) and commuter towns or other locations that draw large numbers of commuterspeople who travel on a daily basis. Trains operate following a schedule, at speeds varying from 50 to 200km/h (30 to 125mph). Distance charges or zone pricing may be used. - The City of New York, often called New York City or simply New York, is the most populous city in the United States. With an estimated 2015 population of 8,550,405 distributed over a land area of just , New York City is also the most densely populated major city in the United States. Located at the southern tip of the state of New York, the city is the center of the New York metropolitan area, one of the most populous urban agglomerations in the world. A global power city, New York City exerts a significant impact upon commerce, finance, media, art, fashion, research, technology, education, and entertainment, its fast pace defining the term "New York minute". Home to the headquarters of the United Nations, New York is an important center for international diplomacy and has been described as the cultural and financial capital of the world. - The Old Main Line Subdivision is a railroad line owned and operated by CSX Transportation in the U.S. state of Maryland. The line runs from Relay (outside Baltimore) west to Point of Rocks, and was once the main line of the Baltimore and Ohio Railroad, one of the oldest rail lines in the United States. At its east end, it has junctions with the Capital Subdivision and the Baltimore Terminal Subdivision; its west end has a junction with the Metropolitan Subdivision. - West Virginia is a state located in the Appalachian region of the Southern United States. It is bordered by Virginia to the southeast, Kentucky to the southwest, Ohio to the northwest, Pennsylvania to the north (and, slightly, east), and Maryland to the northeast. West Virginia is the 41st largest by area, the 38th most populous, and has the second lowest household income of the 50 United States. The capital and largest city is Charleston. - The Baltimore and Ohio Railroad is one of the oldest railroads in the United States and the first common carrier railroad. It came into being mostly because the city of Baltimore wanted to compete with the newly constructed Erie Canal (which served New York City) and another canal being proposed by Pennsylvania, which would have connected Philadelphia and Pittsburgh. At first this railroad was located entirely in the state of Maryland with an original line from the port of Baltimore west to Sandy Hook. At this point to continue westward, it had to cross into Virginia (now West Virginia) over the Potomac River, adjacent to the confluence of the Potomac and Shenandoah rivers. From there it passed through Virginia from Harpers Ferry to a point just west of the junction of Patterson Creek and the North Branch Potomac River where it crossed back into Maryland to reach Cumberland. From there it was extended to the Ohio River at Wheeling and a few years later also to Parkersburg, West Virginia. - The Brunswick Line is a MARC commuter rail line consisting of a main line running from Washington D.C. to Martinsburg, West Virginia, and a branch line from just south of Point-of-Rocks station to Frederick, Maryland. The service is operated under contract by Bombardier Transportation, but is administered by MARC, a service of the Maryland Transit Administration (MTA). The Brunswick Line is MARC's longest line, and operates over CSX's Metropolitan, Old Main Line, and Cumberland Subdivisions. It is the successor to commuter services provided by the Baltimore & Ohio Railroad (B&O) as long ago as the mid-19th century. - A U.S. state is a constituent political entity of the United States of America. There are 50 states, which are bound together in a union with each other. Each state holds administrative jurisdiction over a defined geographic territory, and shares its sovereignty with the United States federal government. Due to the shared sovereignty between each state and the federal government, Americans are citizens of both the federal republic and of the state in which they reside. State citizenship and residency are flexible, and no government approval is required to move between states, except for persons covered by certain types of court orders (e.g., paroled convicts and children of divorced spouses who are sharing custody). - Camden Station, now also referred to as Camden Yards, is a train station at the intersection of Howard and Camden Streets in Baltimore, Maryland, served by MARC commuter rail service and local Light Rail trains. It is adjacent to Oriole Park at Camden Yards. Camden Station was originally built in 1856 by the Baltimore and Ohio Railroad as its main passenger terminal in Baltimore and is one of the longest continuously-operated terminals in the United States. Given the information, choose the subject and object entities that have the relation of 'part of'.
A:
camden line , marc train