Correct Answer: block mountains

Solution : The correct answer is Block Mountains.

The process of formation of mountains is known as orogeny. Block mountains are formed on the earth crust because of tension or faulting. When two blocks compress each other the they move either in upward or downward direction. When there is upward movement it forms block mountains and when it subsides down it forms rift valleys. A block mountain in also known as Horst and the rift valley is also known as graben.