Passive continental margins are characterized by the presence of

Question

A earthquake activity.

B coastal plains.

C oceanic trenches.

D rugged coastal mountains.

Answer 1

Earthquake activity, ocean trenches (due to subducting oceanic plates)and rugged (young) coastal mountains are typically found on active continental margins. (e.i. the west coast of North America.) I don't think it's a rule, but I can't think of a large coastal plain that is on an active plate boundary.

Answer 2

C oceanic trenches. They are caused by inactive plate faults.