Final answer:
The Himalayas were formed by the collision of the Indian Plate with the Eurasian Plate, which is a process of mountain building or orogeny. This tectonic activity causes the mountain range to rise in elevation annually and is an example of a continent-continent convergent boundary.
Step-by-step explanation:
The Himalayas are an example of a mountain range that formed as a result of D. the collision of two continental plates. Specifically, this occurred at a continent-continent convergent boundary, where the Indian Plate collided with the Eurasian Plate. This tectonic plate collision started about 70 million years ago and is still causing the Himalayas to rise in elevation by one to five millimeters per year.
The process is a part of mountain building, or orogeny, which also includes the erosion of mountains by water and ice once they have formed. Unlike mountain ranges formed by other geological processes such as volcanic eruptions or the buildup of sediments, the Himalayas resulted from the direct pressure of tectonic plates pushing against each other under great pressure, folding the Earth's crust, dragging some rock deep below the surface, and raising other folds to great heights.