The best analysis of the reason why Mao Zedong implemented the Cultural Revolution is:
Mao implemented the Cultural Revolution to regain control of the Communist Party after the failures of the Great Leap Forward.
This response accurately captures Mao's motivations, as the Cultural Revolution aimed to reinforce his power, eliminate perceived threats within the Party, and reassert his interpretation of Communist ideology following the widespread economic and social disruptions caused by the Great Leap Forward.