Answer the following question given this paragraph: 

During metamorphism, a rock may change chemically. Ions move in or out of a mineral. This creates a different mineral. The new minerals that form during metamorphism are more stable in the new environment. Extreme pressure may lead to physical changes. If pressure is exerted on the rock from one direction, the rock forms layers. This is foliation . If pressure is exerted from all directions, the rock usually does not show foliation.


Q: If pressure is exerted on the rock from one direction, the rock forms layers. this is called what?

 Choices:

- protonation

- stratification

- sedimentation

- foliation

A:
foliation
