You are presented with the question "What action produces much of the sand from coral?" and the following answer choices: 
- reef building
 - radioactive decay
 - mechanical waves
 - glass blowing
 - It used to be covered by water
 - The area was once underwater
 - Mechanical weathering
 - By coral exoskeletons

Now knowing that the surface of a beach is formed by mechanical weathering and most beaches are of white coral sand, choose the best answer.


 

       Mechanical weathering  