The correct answer to how mountains like the Himalayas are created by plate motion is:
c. Two plates of almost equal density converge and, instead of subducting under one another, they uplift into a mountain.
The Himalayas were formed as a result of the collision between the Indian Plate and the Eurasian Plate. Both plates are relatively thick and of similar density, which causes them to buckle and fold rather than one plate subducting beneath the other. This process leads to the uplift of the land, resulting in the formation of the towering Himalayan mountain range.