Question: Which airport is located in North Dakota, Grand Forks International Airport or Knox County Regional Airport?

full_context: Document 1: Owls Head, Maine: Owls Head is a town in Knox County, Maine, United States. The population was 1,580 at the 2010 census. A resort and fishing area, the community is home to the Knox County Regional Airport. It includes the village of Ash Point.
Document 2: Penobscot Island Air: Penobscot Island Air is a small regional airline based at Knox County Regional Airport, Maine, United States (RKD) operating from a private terminal. The airline operates scheduled service to the islands in Maine's Penobscot Bay, and offers private charter land and seaplane flights throughout the region.
Document 3: Downtown Grand Forks: Downtown Grand Forks is the original commercial center of Grand Forks, North Dakota. Located on the western bank of the Red River of the North, the downtown neighborhood is situated near the fork of the Red River and the Red Lake River. While downtown is no longer the dominant commercial area of the Greater Grand Forks community, it remains the historic center of Grand Forks. An 80.4 acre portion was listed on the National Register of Historic Places in 2005, as Downtown Grand Forks Historic District. Today, downtown Grand Forks is home to many offices, stores, restaurants, and bars.
Document 4: Knox County Regional Airport: Knox County Regional Airport (IATA: RKD, ICAO: KRKD, FAA LID: RKD) is a county owned, public use airport in Knox County, Maine, United States. It is located three nautical miles (6 km) south of the central business district of Rockland, Maine. The airport serves the residents of midcoast Maine with commercial and charter aviation services. Scheduled airline service is subsidized by the Essential Air Service program. It is also a major hub of freight and mail service to Maine's island communities including Matinicus, North Haven and Vinalhaven.
Document 5: Cities Area Transit: Cities Area Transit (CAT) is the public transportation system in the neighboring cities of Grand Forks, North Dakota and East Grand Forks, Minnesota. The scheduled transit bus routes are operated by the city of Grand Forks and service is provided to East Grand Forks through a cost-sharing agreement. Paratransit for those who are unable to use the regular bus under the ADA, and a service for seniors, are provided under contract by Grand Forks Taxi.
Document 6: Minot International Airport: Minot International Airport (IATA: KMOT, ICAO: MOT) is in Ward County, North Dakota, two miles north of the city of Minot, which owns it. The National Plan of Integrated Airport Systems for 2011–2015 categorized it as a "primary commercial service" airport.
Document 7: Fairbanks International Airport: Fairbanks International Airport (IATA: FAI, ICAO: PAFA, FAA LID: FAI) is a state-owned public-use airport located three miles (5 km) southwest of the central business district of Fairbanks, a city in the Fairbanks North Star Borough of the United States state of Alaska. Fairbanks is the smallest city in the United States with non-stop service to Europe, as Condor offers weekly flights to Frankfurt during the summer tourist season. In addition, Air North is another international airline with flights (to Canada) and Antonov Airlines offers cargo flights to South Korea.
Document 8: Grand Forks Municipal Airport: Grand Forks Municipal Airport is a former airport, located within current city limits approximately 3 mi west-northwest of central Grand Forks, North Dakota. It was closed shortly after World War II and is now redeveloped as part of the urban area of Grand Forks.
Document 9: North Haven, Maine: North Haven is a town in Knox County, Maine, United States, in Penobscot Bay. The town is both a year-round island community and a prominent summer colony. The population was 355 at the 2010 census. North Haven is accessed by three-times daily ferry service from Rockland, or by air taxi from Knox County Regional Airport.
Document 10: Knox County Regional Airport: Knox County Regional Airport (IATA: RKD, ICAO: KRKD, FAA LID: RKD) is a county owned, public use airport in Knox County, Maine, United States. It is located three nautical miles (6 km) south of the central business district of Rockland, Maine. The airport serves the residents of midcoast Maine with commercial and charter aviation services. Scheduled airline service is subsidized by the Essential Air Service program. It is also a major hub of freight and mail service to Maine's island communities including Matinicus, North Haven and Vinalhaven.
Document 11: Sugarloaf Regional Airport: Sugarloaf Regional Airport is a public use airport in Franklin County, Maine, United States. It is owned by the Town of Carrabassett Valley and is located one nautical mile (1.85 km) north of the central business district.
Document 12: Grand Forks, North Dakota: Grand Forks is the third-largest city in the State of North Dakota (after Fargo and Bismarck) and is the county seat of Grand Forks County. According to the 2010 census, the city's population was 52,838, while the total of the city and surrounding metropolitan area was 98,461. Grand Forks, along with its twin city of East Grand Forks, Minnesota, forms the center of the "Grand Forks, ND-MN Metropolitan Statistical Area," which is often called "Greater Grand Forks" or "The Grand Cities".
Document 13: Matinicus Isle, Maine: Matinicus Isle is an island plantation in Knox County, Maine, United States. The island is located within Penobscot Bay about 20 miles east of the mainland coast and is accessible by ferry from Rockland or by air taxi from Knox County Regional Airport. The plantation is both a year-round island community and a summer colony. The population was 74 at the 2010 census.
Document 14: Grand Forks International Airport: Grand Forks International Airport (IATA: GFK, ICAO: KGFK, FAA LID: GFK) is a public airport five miles (8 km) northwest of Grand Forks, in Grand Forks County, North Dakota. GFK has no scheduled passenger flights out of the country but has an "international" title (like many other airports) because it has customs service for arrivals from Canada and other countries.
Document 15: Vinalhaven, Maine: Vinalhaven is a town located on the larger of the two Fox Islands in Knox County, Maine, United States. Vinalhaven is also used to refer to the Island itself. The population was 1,165 at the 2010 census. It is home to a thriving lobster fishery and hosts a summer colony. Since there is no bridge to the island, Vinalhaven is accessible from Rockland via an approximately hour-and-fifteen-minute ferry ride across West Penobscot Bay, or by air taxi from Knox County Regional Airport.
ground_truth: Grand Forks International Airport