Answer:
a. the presence of convergent active margins
Explanation:
Some of the abyssal plains also called as underwater plains are found in the Pacific Ocean, as there is the presence of convergent active margins.
When we have to talk about the presence of convergent active margins, primarily we should know about convergent active margins.
Convergent active margins is the point where plates known as oceanic plates meet the plate that is known as the continental plates.
