Question

which part of the shallow ocean descends sharply away from the continental shelf?
abyssal plain
mid - ocean ridge
transitional zone
continental slope

Explanation:

The continental slope is the area that descends sharply from the continental shelf. The abyssal plain is a flat area of the deep - ocean floor. The mid - ocean ridge is an underwater mountain range formed by plate tectonics. The transitional zone is a more general term and not the specific sharply descending part from the continental shelf.

Answer:

continental slope