Question

Which causes the thermocline?

A.
The sun’s radiation heats the surface waters, which descend to the depths and bring colder water to the surface.

B.
The sun’s radiation heats equatorial waters more than polar waters.

C.
The sun’s radiation does not extend below a certain depth; therefore, deeper ocean water is colder than surface water.

D.
The sun’s radiation heats surface waters, causing them to spread out and bring up colder water from the depths.

Answer 1

A.