Answer: option (A)
Explanation: The convection current is generates in the mantle due to the heat radiated from the core of the earth. Due to this convection current, the lithospheric plates moves as the upper part of the mantle known as the asthenosphere, is the region which is viscous in nature and drives the plates to move. This is a repeating cycle that constantly forces the plates to move.
Thus the correct answer is option (A).