Why Does Upwelling Occur Along the West Coast of South

Why does upwelling occur along the west coast of South America, where the Humboldt current flows to the north?

A) The Coriolis effect and Ekman transport deflect the current away from shore, bringing deep water to the surface.
B) The current is high in salinity, causing it to sink and be replaced by deep water.
C) Waves beating against the shore stir up deep water.
D) The surface current is colder than the deep water in that region.