Answer:
d.horizontal deposition
Explanation:
Mountains are formed through a general process called "deformation" (or folding) of the Earth's crust. An example of this kind of folding comes by the process described below.
When two sections of the earth's crust collide, instead of being pushed into deeper regions of the Earth, rock slabs can be stacked on top of each other causing one or both slabs to fold like an accordion.
This process causes the bark to: rise; and fold. In the end, a chain of mountains is formed.
