When two continental plates collide at a convergent boundary, the correct response is:
The plates push up, forming a mountain range.
This occurs because both continental plates are buoyant and resist subduction, leading to the crumpling and uplifting of the Earth's crust, which results in the formation of mountain ranges. An example of this process is the Himalayas, formed by the collision of the Indian Plate and the Eurasian Plate.