Deep, steep-sided valleys that originate on the continental slope and may extend to the ocean basin floor are called a abyssal plains b slope canyons c submarine canyons d trenches

The correct answer is option c, that is, submarine canyons.

A submarine canyon refers to a steep-sided valley cut into the seabed of the continental slope, at certain occasions, outspreading well onto the continental shelf, possessing almost vertical walls, and occasionally exhibiting canyon wall heights of up to 5 kilometers, from the floor of the canyon to the rim of the canyon, like the Great Bahama Canyon.

i think its c. amphipod

there's the proffessional site that will you.