In Addition to the Years of the Great Proletarian Cultural

In addition to the years of the Great Proletarian Cultural Revolution, the "ten lost years" also refers to the

A) decade of the 1930s when the Communists were confined to Yan'an.
B) years of the 1920s when the Chinese Communist Party was allied to Chiang Kai-shek's Nationalist Party.
C) decade after Mao's death when the economy experienced a disastrous depression.
D) years after 1949 when China was largely isolated from the West and its technology.
E) era of the New Democracy.