The End of the Great Proletarian Cultural Revolution Occurred When​

The end of The Great Proletarian Cultural Revolution occurred when​

A) ​Deng Xiaoping ascended to power and changed the emphasis of Communism to economic modernization.
B) ​Pro-democracy forces within China rebelled against the Red Guards.
C) ​The Helsinki Accords documented brutalities by the Red Guard.
D) ​Moderate forces within the government denounced it as a propaganda movement like Socialist Realism.
E) ​Democracy was introduced to China.