3. In the mid-1980s, researchers determined there were only 1,000 giant pandas left in the wild. In 2004, the giant panda population reached 1,600. Based on the text, what is one thing that may have caused this increase?
A. decrease in the population of China
B. increase in the population of China
C. increased logging in the bamboo forests of western China
D. the Chinese government's ban on logging