Answer:
Part A: The boundary being described in the passage is a convergent boundary, where two tectonic plates are colliding. The two plates involved are the Indian plate and the Eurasian plate.
Part B: The geologic process that led to the formation of the Himalaya Mountains began around 80 million years ago when the Indian subcontinent collided with the Eurasian plate. The Indian plate was driven beneath the Eurasian plate, causing the uplift of the Eurasian plate and the subsequent formation of the Himalaya Mountains. This collision continues today, as the Indian plate continues to push under the Eurasian plate, causing the mountains to continue to rise. The process of one plate being driven beneath another is called subduction, and it is a common process that forms mountain ranges around the world.