How do waves change as they approach the shore? A. The height of the waves decreases B. The distance between crests decreases C. Friction acting on the top of the wave increases D. The wavelength increases

The answer to this is B.

Correct answer is: " B. The distance between crests decreases"

When the waves approach the shore, they start to get closer and closer to the sea floor slowing down because they now find friction at the bottom. This phenomenon leads the crests of the waves to become closer (their inter distance decreases). They crests start to increase in height as the waves compress each other and they keep coming at the same frequency.