Concept:Fold mountains are formed by the horizontal squeezing of the Earth’s crust.
Explanation:When two tectonic plates collide, they push against each other.
This pushing creates compressional forces in the crust.
These forces squeeze layers of sedimentary rocks, causing them to buckle and fold.
The folded rocks rise upward to form fold mountain ranges.
Faulting mainly produces block mountains, not fold mountains.
Vulcanicity forms volcanic mountains, while tensional forces pull the crust apart.
Therefore, compressional forces are the primary cause of fold mountain formation.
Answer:C. Compressional forces