Seamounts are. a) volcanoes that form on the ocean floor
b) a special type of oceanic trench
c) submarine canyons found near Australia

A

Explanation:

Seamounts are underwater mountains that rise hundreds or thousands of feet from the seafloor. They are generally extinct volcanoes that, while active, created piles of lava that sometimes break the ocean surface.

a

Explanation:

seamounts are underwater mountains that rise hundred or thousand of feet from the seafloor. They are generally extinct volcanoes that, while actve, created piles of lava that sometimes break the ocean surfaces

the answer is the last option or letter d)