Here's a problem to solve: Long shore currents are ocean waves that strike beaches at extremely small angles. In areas where long shore currents exist, what effect do they have on land areas?

Among the 4 following options, which is the correct answer?

- A: They build mountains.
 
- B: They cause earthquakes.
 
- C: They move sand, creating sandbars.
 
- D: They create inland saltwater rivers.
 