What Was the Primary Force Behind the Formation of the Himalayas

Multiple Choice

What was the primary force behind the formation of the Himalayas?

A) the collision of peninsular India with the Eurasia continental plate
B) the rifting (pulling apart) of the Eurasian Plate and the Indo-Australian Plate
C) the erosion of the landscape north and south of the region that would become the mountains
D) the upwelling of molten matter from a hot spot beneath the Indian subcontinent
E) major volcanic activity