Given this reference text about Bougainville Island, what is its land area?

Context: Bougainville Island is the main island of the Autonomous Region of Bougainville, which is part of Papua New Guinea. It was previously the main landmass in the German Empire-associated North Solomons. Its land area is 9,300 km2. The population of the whole province, including nearby islets such as the Carterets, is approximately 300,000. The highest point is Mount Balbi, on the main island, at 2,715 m. The much smaller Buka Island, c. 500 km2, lies to the north, across the 400–500 m wide Buka Strait. Even though the strait is narrow, there is no bridge across it, but there is a regular ferry service between the key settlements on either side. The main airport in the north is in the town of Buka.

Answer: Its land area is 9,300 km2 (3,600 sq mi).