Question

what is the source of energy that causes surface currents in the ocean?
a. density differences between freshwater and seawater
b. the magnetic attraction between the north and south poles
c. the gravitational pull of the moon and the sun on the ocean
d. winds created by the uneven heating of air on earth by the sun

Explanation:

Surface - ocean currents are mainly driven by wind. Wind is generated due to the uneven heating of the Earth's atmosphere by the Sun. Density differences cause thermohaline circulation, the magnetic poles' attraction is not related to surface - ocean currents, and the gravitational pull of the Moon and Sun causes tides.

Answer:

D. winds created by the uneven heating of air on Earth by the Sun