What has a direct effect on precipitation and climate

Ocean currents have a effect on precipitation and climate. The ocean currents bring warm water to cold places and vice versa. Without the ocean currents being the way they are, we would have the climate we have today. The precipitation part of my answer is pretty obvious. The ocean is water and water evaporates and makes clouds and then the clouds rain.

The answer is b im not sure 

Climate change to earth function human can't reduce climate