Answer: Option (D) is the correct answer.
Explanation:
Deep water currents arises due to the wind. Therefore, hot molecules (less dense) sinks at the bottom and cool molecules (more dense) rises at the top.
This process of inter-conversion of molecules from top to bottom and bottom to top is known as convection.
Thus, we can conclude that out of the given options convection is the process involved in deep water currents.
