Mountains are formed by

• A. Tectonic Plates Moving Together (Convergent Collision Boundary)
• B. Tectonic Plates Moving Away From One Another (Divergent Boundary)
• C. Tectonic Plates Slipping One Under Another (Convergent Subduction Boundary)
• D. Tectonic Plates Sliding Past Each Other (Transform Boundary)

Answer: (A)

Mountain formation happens when tectonic plates collide and push against each other, thickening and uplifting the crust at convergent boundaries. When two continental plates converge, neither readily sinks, so the crust buckles and crumples, building tall mountain ranges such as the Himalayas. Divergent boundaries pull plates apart to create new crust and often form rift valleys, not tall mountains. Transform boundaries involve plates sliding past one another, causing earthquakes along faults rather than significant crust thickening. So the collision and uplift at convergent boundaries is the main process that creates major mountains.