In which of the following sentences is the word leaves a verb?

A. I have spent all after noon raking leaves because we have over twenty trees in our yard.

B. The young boys leaves his legos all over the floor, and his parents are constantly stepping on them.

C. When the leaves begin to fall, the weather is turning cooler.

D. I hope the levees hold with all of this rain; we don't need floods this year.