When the united states dropped atomic bombs on japan, it triggered the start of a race between the united states and the soviet union. this was a key issue during the cold war.

a. nuclear arms
b. space travel
c. climate change
d. global peace

The correct answer is option A. "Nuclear Arms".

Explanation:

When United States dropped atomic bombs in Hiroshima, and three days later in Nagasaki, it marked the end of World War II. This also marked the start of a nuclear arms race between the two dominant forces of the world: United States and the Soviet Union. This nuclear arms race was a key issue of the Cold War, having a series of tests that increase the tension between the two countries who looked for supremacy in nuclear warfare.

the difference is that white collar worker performs skills like worker as a scientist or well blue collars do physical work and they do services like being a cook.