I’m gonna go with answer D.c because the ocean had very deep trenches
A succession of ocean waves set in motion by a submarine earthquake (also known as underwater earthquake) is called a tsunami. This happens when tectonic plates move, converge, or subduct. Submarine earthquakes are common in Asia where there’s a submarine earthquake zone called Pacific Ring of Fire.
To find the mid point,here's the formula:

In this case:
((5+1)/2,(5+2)/2)
=(6/2,7/2)
=(3,3.5) or (3,7/2)
Therefore the answer is (3,3.5) or (3,7/2).
Hope it helps!