Quoc: Ronald Reagan Washington National Airport (IATA: DCA, ICAO: KDCA, FAA LID: DCA) is an airport in Arlington, Virginia that acts as the primary airport serving Washington, D.C.. It is the nearest commercial airport to the capital and serves the Baltimore -- Washington metropolitan area. For decades it was called Washington National Airport before being renamed to honor President Ronald Reagan in 1998. The Metropolitan Washington Airports Authority (MWAA) operates the airport with close oversight by the federal government due to its proximity to the national capital.

What does the airport code dca stand for?
HW Chung: OK, some thoughts:
The relevant sentence in the passage is: Ronald Reagan Washington National Airport (IATA: DCA, ICAO: KDCA, FAA LID: DCA) is an airport in Arlington, Virginia that acts as the primary airport serving Washington, D.C.. The answer is Ronald Reagan Washington National Airport.