Question

the cultural revolution ultimately failed because
human rights violations led to a foreign invasion.
thousands of chinese government officials left office.
the chinese people began to question their faith in communism.
famine killed millions of people across the country.

Explanation:

1. Analyze Option 1: There was no foreign invasion due to human rights violations during the Cultural Revolution. So this option is incorrect.
2. Analyze Option 2: Thousands of Chinese government officials left office was a result of the Cultural Revolution's chaotic situation, but not the reason for its failure. So this option is incorrect.
3. Analyze Option 3: The Cultural Revolution caused great chaos and damage to the country, which made the Chinese people begin to question the implementation of communism in this wrong way, and this was one of the important reasons for its ultimate failure. This option conforms to historical facts.
4. Analyze Option 4: The famine that killed millions of people was during the Great Leap Forward, not the Cultural Revolution. So this option is incorrect.

Answer:

C. the Chinese people began to question their faith in communism.