A. What causes wind-driven currents?

Question

A. What causes wind-driven currents?

Answer 1

Wind.

Answer 2

Wind.  The frictional force of air moving over a body water will cause the water molecules to move in the same direction as the wind is blowing.  

The water molecules will sort of "stack up" as the wind pushes them.   They will then form wind driven waves.  The higher the wave is above the mean surface level the more wind resistance it has, therefore is more subjected to the forces of the wind.

Answer 3

But maybe you want more than wind.  Wind and currents are both caused by a combination of convection (the movement of air or water from a warmer area to a cooler area) and the Coriolis Effect (the veering of fluids to the right or left, depending upon hemisphere, caused by the earth's rotation on its axis.