The answer is C The stability allowed aleut and alutiig populations to grow
The Red Scare was the term to describe that
The US government's decision to develop a hydrogen bomb, first tested in 1952, committed the United States to an ever-escalating arms race with the Soviet Union. The arms race led many Americans to fear that nuclear war could happen at any time, and the US government urged citizens to prepare to survive an atomic bomb.
The Declaration summarized the colonists' motivations for seeking independence. By declaring themselves an independent nation, the American colonists were able to confirm an official alliance with the Government of France and obtain French assistance in the war against Great Britain.
All of the countries were having a battle of who could build the biggest bombs, guns, tanks, weapons, technology, etc. which created tension between rival countries. everyone was afraid of the next country being too powerful. Hope it makes sense :-)