Question: Which building that became a National Historic Landmark in 1994 is in a district added to the National Register of Historic Places in 1975?
Context: The Ochre Point–Cliffs Historic District is a historic district in Newport, Rhode Island.  The district includes a significant subset of the Bellevue Avenue Historic District, a National Historic Landmark District, including all of the major Gilded Age mansions on the waterfront facing Easton Bay between Memorial Boulevard and Marine Avenue.  The district is home to famous mansions such as the William Watts Sherman House and The Breakers, one of the largest houses in the area built by the Vanderbilt Family.  The district was added to the National Register of Historic Places in 1975. Loop Retail Historic District is a shopping district within the Chicago Loop community area in Cook County, Illinois, United States.  It is bounded by Lake Street to the north, Congress Parkway to the south, State Street to the west and Wabash Avenue to the east.  The district has the highest density of National Historic Landmark, National Register of Historic Places and Chicago Landmark designated buildings in Chicago.  It hosts several historic buildings including former department store flagship locations Marshall Field and Company Building (now Macy's at State Street), and the Sullivan Center (formerly Carson, Pirie, Scott and Company Building).  It was added to the National Register of Historic Places on November 27, 1998.  It includes 74 contributing buildings and structures, including 13 separately listed Registered Historic Places, and 22 non-contributing buildings.  Other significant buildings in the district include the Joffrey Tower, Chicago Theatre, Palmer House, and Page Brothers Building.  It also hosts DePaul University's College of Commerce, which includes the Kellstadt Graduate School of Business and the Robert Morris College. The Greendale Historic District is a National Historic Landmark District encompassing the historic core of the village of Greendale, Wisconsin.  The village core was designed in the 1930s as part of a New Deal program to establish so-called "greenbelt towns" as model suburbs, and is one of three such communities built by the federal government.  It was added to the National Register of Historic Places in 2005 and designated as a National Historic Landmark in 2012. The Gallaudet College Historic District is a National Historic Landmark District encompassing the historic early campus of Gallaudet University in Washington, D.C..  Gallaudet is the first school of higher education to be devoted to the education of the deaf and hard of hearing.  Its campus was planned by Frederick Law Olmsted and Calvert Vaux, and its Gothic buildings were designed by Frederick Withers.  The main Gallaudet College building was listed on the National Register of Historic Places in 1966 and designated a National Historic Landmark in 1965.  The landmarked area was increased to cover the southern part of the campus, and was renamed as a historic district in 1974. The Port Townsend Historic District is a National Historic Landmark District encompassing a significant portion of the waterfront and downtown area of Port Townsend, Washington.  This area has many well-preserved late 19th-century buildings, owing to a building boom and crash in the 1880s.  The result is one of the finest examples of a late 19th-century port town on the west coast.  The historic district was listed on the National Register of Historic Places in 1976, and was designated a National Historic Landmark in 1977. The Nantucket Historic District is a National Historic Landmark District that encompasses the entire island of Nantucket, Massachusetts.  The original December 13, 1966 listing on the National Register of Historic Places included only the historic downtown core and the village of Siasconset, but was expanded in 1975 to include the entire island, as well as the islands of Tuckernuck and Muskeget.  At over 30,000 acres, it is the largest conventional historic National Historic Landmark District by area in the contiguous United States. The Breakers is a Vanderbilt mansion located on Ochre Point Avenue, Newport, Rhode Island, United States on the Atlantic Ocean.  The building became a National Historic Landmark in 1994, and is a contributing property to the Bellevue Avenue Historic District.  It is owned and operated by the Preservation Society of Newport County and is open for visitation on a year-round basis. The Printing House Row District is a National Historic Landmark District encompassing four architecturally important buildings on the 300 through 500 blocks of South Dearborn, South Federal and South Plymouth streets in the Loop community area of Chicago, Illinois.  It was listed on the National Register of Historic Places as South Dearborn Street – Printing House Row Historic District and listed as a National Historic Landmark as South Dearborn Street – Printing House Row North Historic District on January 7, 1976.  The district was designated a Chicago Landmark on May 9, 1996.  The district includes the Monadnock Building, the Manhattan Building, the Fisher Building, and the Old Colony Building.  The district overlaps significantly with the Printers Row neighborhood, and is not the same as South Loop Printing House District. This is a list of historic properties in Tombstone, Arizona, which includes a photographic gallery of some of the remaining historic structures.  The majority of these structures are in the Tombstone Historic District which was declared a National Historic Landmark in 1961.  The District was added to the National Register of Historic Places on October 15, 1966, reference #66000171.  Included are the photographs of individual properties identified as historic by the National Register of Historic Places.  These include the Sacred Heart Church, St. Paul’s Episcopal Church, the Tombstone City Hall and the Tombstone Courthouse.  Also included is the historic Boot Bill Graveyard with images of the graves of some of the town's notable internees. The Harry S. Truman Historic District is a National Historic Landmark District encompassing sites closely associated with US President Harry S. Truman in Independence, Missouri.  It includes the Truman Home at 219 North Delaware, Truman's home for much of his adult life and now a centerpiece of the Harry S. Truman National Historic Site, and the Truman Presidential Library.  The district was listed on the National Register of Historic Places in 1971, and was designated a National Historic Landmark in 1974.  When first listed, the district included only the two buildings and a corridor joining them.  It was substantially enlarged in 2011 to include more sites and the environment in which Truman operated while living in Independence.
Answer: The Breakers