Answer:
D
Explanation:
It's not A since the rebuilding of Germany did NOT affect the Cold War in any influential way.
It's not B since they were the middle ground between communist and non-communist countries and weren't allowed to aid the US and they did not own any nuclear power themselves
It's not C since they had no power to rearm any leadership or repair anything individually.
Their main purpose is to keep the peace between countries so the best answer is D