Which boundary leads to mountain formation when continents collide?

• A. Continental-Continental Boundary
• B. Oceanic-Oceanic Boundary
• C. Transform Boundary
• D. Divergent Boundary

Answer: (A)

Continental-continental collision at a convergent boundary causes mountain formation because the buoyant continental crust resists subduction, so the rocks are squeezed, thickened, and pushed upward to form mountain ranges. The Himalayas show this process, created by the ongoing collision of the Indian and Eurasian plates. Other boundary types behave differently: oceanic-oceanic convergence involves one plate subducting beneath the other, forming trenches and volcanic island arcs; transform boundaries cause lateral sliding that mostly produces earthquakes rather than tall mountains; divergent boundaries pull plates apart, creating rift valleys and new crust, not large continental mountains.