Active volcanoes are most likely to form at or near- A. Transform plate boundaries
B. A convergent continental continental plate boundary
C. The center of the continents
D. A conversion oceanic continental continental plate boundary( subduction boundaries)

A convergent oceanic-continental plate boundary (subduction boundaries).

Explanation:

Volcanoes form two types of plate boundaries, but also in the interior of the continental plates where there are hot spots below. The two types of plate boundaries where volcanoes can be found are the convergent and divergent plate boundaries, with the first ones having the vast majority of the volcanoes above the surface, while the second ones have the vast majority below the water surface.

At convergent plate boundaries, especially where continental and oceanic plates collide, there are volcanoes all across the plate boundary. This is due to the formation of a subduction zone, where the crust gest much more fragile around it and magma manages to push through and come out on the surface very easily. In practice, this can easily be seen by the fact that the majority of the volcanoes are found in the so-called ''Ring of Fire'' where there are numerous convergent boundaries between continental and oceanic plates.