Carlos is looking at a picture of a convergent boundary on which a volcanic arc and a trench are identified. which type of convergent boundary is carlos looking at?

The answer would be:

Oceanic-Oceanic Convergent Plate

This is why:

When two oceanic plates collide, the heavier of the two would subduct or in other words, go under the other plate. When this happens, ocean trenches and volcanic arcs form. The trench forms at the point oceanic plate goes under the other plate. And above the other plate that goes over create volcanic arcs.  

the positions which points up in upward carbon and down in downward carbon are axial

and vice versa holds true for equatorial positions

so the correct answer with labelled diagram will be