Which landform was most likely formed by deposition?

A. cave
B. cliff
C. beach
D. arch

C. beach?

Right.

Which of the following is caused by ocean waves and the wind?

A. earthquakes
B. tides
C. sand dunes
D. hurricanes

B.tides?

Nope.

http://en.wikipedia.org/wiki/Dune

You are correct! The landform most likely formed by deposition is a beach. Deposition refers to the process of sediment being carried and deposited by water, wind, or ice. In the case of beaches, sediment (such as sand and rocks) is transported by ocean currents and waves, and is then deposited along the coastline. Over time, this accumulation of sediment creates a beach.