Question

Which of the following is a direct cause of surface currents?

A.
uneven heating

B.
high salinity

C.
differences in density

D.
wind forces

Answer 1

Ocean currents are continuous and directed movements of ocean water horizontally and vertically. The major causes of currents are wind friction, Gravitation of the moon and earth and Planet rotation.
Source : http://www.ask.com/question/what-causes-most-surface-ocean-currents