The answer is C. The atmosphere is essentially the surroundings of anything. In the case of the earth, however, it is gasses.
Answer:
Protect itself from attack.
Explanation:
The US attempted to gain influence to protect itself from such "Evil Commie ideals" via foreign influence. An example of this is Vietnam, where despite the US not being directly threatened, the government was acting convincing in the argument that "the domino effect" would soon reach the US, and anarchy would fall upon all western civilized nations. A bit exaggerated, but makes sense.
The answer is B) Secularism.
World war 1,
Italy became officially unified