thermal potential chemical mechanical
I gave my students this multiple choice question: One key physical process in beach formation is wave action. Sand is deposited on beaches as waves break onto the shoreline and the energy from the wave scatters. Which type of energy is most used by wave action to modify the shape of the beaches?

Only one answer is correct among these 4 choices:
- thermal
- potential
- chemical
- mechanical

Could you tell me which one is correct?

mechanical