Mountain ranges often appear on the edges of continents. The earth would of had to smash together to make the land go up into the air. A mountain range or a hill range is a series of mountains and/or hills arranged in a line and connected by high round. Mountain ranges are a result, in most cases, of a geological process called a plate tectonics, which is the motion of large plates, like continents. This theory that supports the concept of continents colliding, explains why there are mountain ranges.
So the answer is B: Over time, from the earth's plates pushing on each other.
