which of the following is associated with mountain building?
a: contact sedimentation
b: regional metamorphism
c: contact metamorphism
d: regional volcanism

Regional volcanism is associated with mountain building.

Option D

Explanation:

Mountain building which is also known as the orogeny is the geological process such as movement of tectonic plates and volcanic activities because of which the mountains are formed by the pressure on the earth's crust when the plates collide.

So the occurring of volcanoes in a particular region along the plate boundaries where there is some movement in the tectonic plates might result in the formation of a mountain.  

the awnser is a

it is not b or c