The correct answer is - B) wave erosion.
The beach erosion is a direct result of the wave action on the coastline. The waves are very powerful when it comes to erosion, and this is because they have big power, and also the chemical components of the water that are very effective too.
The sheer power of the waves contributes to the direct breaking of the rocks into smaller pieces over time, while the water itself, is reacting with the rocks on a chemical level and slowly decomposes them. As the rocks are getting smaller and smaller because of the erosion, the tiny fractions of sand particles are forming the beaches along the coastlines.
