Why is Kaliningrad an exclave?
A. It is a part of Poland separated geographically from the main part of Poland by foreign territory.
B. It is a part of Ukraine separated geographically from the main part of Ukraine by foreign territory.
C. It is a part of Russia separated geographically from the main part of Russia by foreign territory.
D. It is a part of China separated geographically from the main part of China by foreign territory.