Question: Which regional airline, which is headquartered in Delta Air Lines Building C at Minneapolis-Saint Paul International Airport, is one of three holdings for a privately owned holding company, headquartered in Bridgetown, Missouri?
Context: Pinnacle Airlines Corporation was an American holding company headquartered in Memphis, Tennessee, and was the parent company of Pinnacle Airlines and Colgan Air until Colgan was closed down in 2012.  The company contracted its airlines to fly in the aircraft livery of other airlines such as Delta Air Lines and United Airlines.  The company filed for bankruptcy protection under Chapter 11 in 2012 and emerged from Chapter 11 in 2013 as a wholly owned subsidiary of Delta Air Lines.  The company's only surviving airline, Pinnacle, became Endeavor Air. Compass Airlines, LLC, is a regional airline headquartered in Delta Air Lines Building C at Minneapolis−Saint Paul International Airport in Fort Snelling, Hennepin County, Minnesota; prior to December 16, 2009, it was headquartered in unincorporated Fairfax County, Virginia, United States, east of the Chantilly CDP.  The airline launched inaugural service with a single Bombardier CRJ200LR aircraft under the Northwest Airlink (now Delta Connection) brand between Minneapolis/St.  Paul and Washington, D.C. on May 2, 2007.  On August 21, 2007, it began flying two Embraer 175 76-passenger aircraft, and expanded to 36 aircraft by December 2008. Regional Elite Airline Services (formerly announced as Regional Handling Services), which began operations on September 27, 2009, was a wholly owned subsidiary of Delta Air Lines that combined all airport ticket counter, gate, tower coordination, and ramp handling duties for Comair, Compass Airlines, and Mesaba Airlines.  Its headquarters are in Delta Air Lines Building C on the property of Minneapolis-St.  Paul International Airport, in Fort Snelling, an unincorporated area. Trans States Holdings, Inc. is a privately owned holding company for three regional airlines: Compass Airlines, GoJet Airlines and Trans States Airlines.  The holding company is headquartered in Bridgeton, Missouri near the Lambert-St.  Louis International Airport. Endeavor Air is an American regional airline that operates as Delta Connection for Delta Air Lines.  The airline was founded as Express Airlines I in 1985 and changed names to Pinnacle Airlines in 2002.  In 2012, Pinnacle's parent company filed for chapter 11 reorganization, then emerged as a wholly owned subsidiary of Delta Air Lines.  The name of the airline was changed to Endeavor Air on August 1, 2013. SkyWest Airlines is a North American airline owned by SkyWest, Inc. and headquartered in St. George, Utah, U.S..  According to the Airlines for America definitions, SkyWest is a North American major airline.  SkyWest however, operates on a regional airline level and is a member of the Regional Airline Association.  SkyWest Airlines flies to 238 cities, in 45 states; Washington, D.C., six Canadian provinces and five cities in Mexico.  The airline serves as a feeder airline, operating under contract with various major carriers.  It flies as SkyWest Airlines in a partnership with Alaska Airlines, as United Express on behalf of United Airlines, as American Eagle on behalf of American Airlines, and as Delta Connection on behalf of Delta Air Lines.  SkyWest also provides ground handling services for airports across the United States. Republic Airlines (IATA: RC, ICAO: REP, Call sign: REPUBLIC) was a United States airline formed by the merger of North Central Airlines and Southern Airways on July 1, 1979.  Their headquarters were at Minneapolis-St.  Paul International Airport, in what is now Fort Snelling in unincorporated Hennepin County, Minnesota.  The former headquarters is now Delta Air Lines Building C. Republic was acquired by and merged into Northwest Airlines in 1986. Delta TechOps is the maintenance, repair and overhaul (MRO) division of Delta Air Lines, and is headquartered at Hartsfield-Jackson International Airport (ATL) in Atlanta, Georgia.  With more than 9,600 Technical Operations employees and 51 maintenance stations worldwide, Delta TechOps is a full-service maintenance provider for the more than 750 aircraft that make up the Delta Air Lines fleet.  In addition to maintaining the Delta Air Lines fleet, Delta TechOps also provides MRO solutions and support to more than 150 third-party operators around the world, making it the largest airline MRO provider in North America and the third largest worldwide. The Minneapolis-Saint Paul Metropolitan Airports Commission (MAC) is the owner and operator of Minneapolis-Saint Paul International Airport in Minnesota as well as six other reliever airports in the Twin Cities region, which primarily provide service to private individuals and businesses, but also have regional transportation service. Champion Air was an airline based in Bloomington, Minnesota, USA.  It operated general charter services to sports teams, vacation wholesalers and government agencies.  It also offered limited scheduled service.  Its main base was Minneapolis-Saint Paul International Airport, with hubs at Denver International Airport, Dallas-Fort Worth International Airport, Detroit Metropolitan Wayne County Airport, McCarran International Airport in Las Vegas, Lambert-St.  Louis International Airport, and Will Rogers World Airport in Oklahoma City.  The airline ceased all operations on May 31, 2008.  Until its shutdown, the airline was a prime contractor for the Justice Prisoner and Alien Transportation System.
Answer: Compass Airlines