Which type of intrusive feature forms when magma is injected into fractures cutting across rock layers?
a. a laccolith
b. a dike
c. a lava plateau
d. a sill

The answer is Dike.
In Geology, Dike is a sheet of rock formed in a fracture in a pre-existing rock body. Magmatic dikes are formed when magma intrudes into a crack then crystallize. It is an igneous body with a very high aspect ratio.

Answer collision and mountain formation;