The movement of deep ocean currents is mainly caused by: ?

The relationship between the density of ocean water and the formation of deep currents. Difference in the tempature and salinity and the resulting differences in density cause variations int he movement of deep currents. For example, the deepest current , The Antarctic Bottom Water, is denser than the North Atlantic Deep Water. Both currents spread across the ocean floor as they flow toward eachother. Because less dense water always flows on top of denser water, The north Atlantic Deep Water flows on top of the Atlantic Bottom Water when the currents meet.

Ithink the answer is c but then again i'm probably wrong