Which of the Following Led to Increased Agricultural Production in China

Which of the following led to increased agricultural production in China in the late 1970s?

A) The government sponsored new farming methods that were superior to their competitors.
B) Chinese agronomists bred new strains of rice that were immune to plant diseases.
C) China's climate was well suited for food production,especially in the western and northern parts of the country.
D) The government broke up some collectives and restored the family as the basic economic unit in rural areas.