Answer :
Immediately after WWII, the relationship between the U.S. and the Soviet Union became strained because - "competing ideology - each country believed that the other one was a threat to its security" (Option C)
Each country, representing capitalism and communism respectively, viewed the other as a threat to its security and global influence. This ideological divide led to the Cold War, characterized by political, economic, and military tensions.
While events such as the Korean War and the Soviet Union's exclusion from the United Nations exacerbated tensions, they were symptomatic of the broader ideological struggle rather than the primary cause.
Space exploration competition emerged later in the Cold War era and contributed to ongoing tensions but wasn't the initial trigger for strained relations.
Thus, the right option is C.
Full Question:
Although part of your question is missing, you might be referring to this full question:
Immediately after WWII, the relationship between the U.S. and the Soviet Union became strained because -
A) the U.S. used military force in Korea
B) the U.S. blocked the Soviet Union from joining the United Nations
C) competing ideology - each country believed that the other one was a threat to its security
D) both nations were competing for supremacy in space exploration
