What Is the Point of Mencius's Analogy Between Water and Human

Multiple Choice

What is the point of Mencius's analogy between water and human nature in 6A1?

A) That, as with water, just because humans can be forced to behave in a certain way does not mean they are naturally like that.
B) That, just as water naturally flows downhill, so humans' virtue naturally declines unless it is protected through study and reflection.
C) That, just as water will flow whichever way it is channeled, human nature can be changed by different customs and behaviors.
D) That, as with water, humans will always find a way to reveal their true nature eventually.