What problem has China tried to solve by building hydropower dams, such as the Three Gorges Dam?

A.scarcity of water>>>>>

B.lack of arable land

C.production of greenhouse gases

D.damage from earthquakes and tsunamis

(why do i think it is A because Dam construction has played significant roles in flood control, irrigation, navigation, and energy supply; however, the enormous negative effects, such as landslides, ecological problems, and Water Quality decline, could surpass positive gains.)