Since sea level is not dropping, what are the other sources of water for the oceans in addition to precipitation?

I think it could possibly be runoff from groundwater into the oceans.

Ibelieve the answer is c

Sequoia national park  /  inyo national forest, california, u.s. mount whitney is the tallest mountain in california, as well as the highest summit in the contiguous united states and thesierra nevada—with an elevation of 14,505 feet (4,421 m).