The correct answer is A. the Gang of Four's rise to political power.
To provide context:
- The founding of the Communist Party of China occurred in 1921 (D).
- The Great Leap Forward economic program was implemented from 1958 to 1962 (C).
- The Great Proletarian Cultural Revolution took place from 1966 to 1976 (B).
- The Gang of Four, which was a political faction led by Jiang Qing, rose to significant power in the early 1970s, and their influence continued until their arrest in 1976, following Mao Zedong's death.
Thus, the Gang of Four's rise to power occurred last.