What significance does October 1, 1949, have in Chinese history?

A. The Boxer Rebellion was defeated by foreign troops
B. The last dynasty ended with the death of its empress.
C. Mao Zedong declared China the "People's Republic of China."
D. China ended its self-imposed isolation

C. Mao Zedong declared China the "People's Republic of China."

October 1, 1949, is the day when Mao Zedong officially declared the establishment of the People's Republic of China, marking the end of the Chinese Civil War and the beginning of Communist rule in China. This event is considered a significant moment in Chinese history as it marked the culmination of years of conflict and marked the beginning of a new era for the country.