Answer:
C. The Soviet Union successfully tested their own atomic bomb when they dropped it on Hiroshima Japan.
Explanation:
The city of Hiroshima in Japan, in fact, was attacked by an atomic bomb at the end of World War II. However, this bomb was not dropped by the Soviet Union, but by the US as a way to make the Japanese army retreat and surrender, thus ending World War II. This moment was considered one of the worst moments of the war.