Question

the himalayan mountain range was formed by
continental - continental crust collisions
convergent boundary volcanism
hot spot volcanism
island arc formation

Explanation:

The Himalayan Mountain Range was formed due to the collision of the Indian continental crust with the Eurasian continental crust. This is a classic example of continental - continental crust collisions. Convergent boundary volcanism is more associated with subduction zones where one plate (usually an oceanic plate) is subducting beneath another. Hot spot volcanism creates volcanic features like the Hawaiian Islands. Island arc formation is related to subduction of oceanic plates and the formation of arcs of islands, not mountain ranges like the Himalayas.

Answer:

continental - continental crust collisions