Which of the following occurs at convergent plate boundaries?
a.
subduction zone
b.
island arc
c.
mountain formation
d.
all of the above

Option (D)

Explanation:

In a convergent plate motion, the two plates move towards each other. Due to this, a subduction zone is created that is often marked by a deep-sea trench. It also results in the deep-focus earthquakes. Here, the subducting plate mixes with the melt at great depth and the magma eventually rises up forming island arcs and volcanic arcs.

In an oceanic-oceanic convergent boundary, island arcs are formed and in the continental-oceanic convergent boundary, volcanic arcs are formed.

Lastly, in the continental-continental convergent boundary, huge mountain belts like Himalaya are formed.

Thus, the correct answer is option (D).