Question: What is the busiest airport in the region including  Central Maryland and Northern Virginia?
Sentence (from "Baltimore–Washington International Airport"): Baltimore/Washington International Thurgood Marshall Airport (IATA: BWI, ICAO: KBWI, FAA LID: BWI) is an international airport located in Linthicum in northern unincorporated Anne Arundel County, Maryland.
Relevant evidence: Yes