Final answer:
The Appalachian Mountains and the Himalayas were created through the geological process of faulting and folding due to tectonic plate collisions.
Step-by-step explanation:
The Appalachian Mountains and the Himalayas are examples of mountain ranges created by faulting and folding, which is a result of tectonic plate collisions. When two continental plates collide, they exert tremendous pressure, causing the Earth's crust to buckle and fold. This process pushes rock upwards forming mountain ranges like the Himalayas.
The Appalachian Mountains have a complex geological history involving multiple tectonic events and extensive erosion over millions of years. Erosion by water and ice sculpts the mountains further, but the mountains themselves are initially formed by tectonic activity, not through erosion. Therefore, the correct answer to the question is c) Faulting and folding.