What is most likely to occur where one tectonic plate is forced under another tectonic plate?

Subduction zone, trench and volcanic or island arc

Explanation:

During a convergent plate motion, two plates move towards each other. Due to this motion, the denser plate subducts below the lighter plate, as a result of which a subduction zone is created, which is usually marked by the presence of a trench above this zone of subduction. As the denser plate sinks, it melts at large depth, and magma eventually rises up mixing up with the melt, towards the surface in the over-riding plate, giving rise to the formation of volcanoes or volcanic arcs and island or island arcs.

Thus, this type of boundary is known as the convergent type of plate boundary.