Which of the following were reasons for the Soviet Union’s collapse? i. Satellite nations declared independence.

ii. The Soviet Union could not compete economically with the West.

iii. Soviet citizens demanded political and economic reforms.

iv. The United States beat the Soviet Union in a violent battle at Stalingrad.

A. i. and ii. only

B. i. and iv. only

C. iii. and iv. only

D. i., ii., and iii.