Question

Folding occurs because:

the earth's crust is moving
magma builds up below the surface
wind and water erode current land masses
sedimentary rocks easily crack under pressure

@masterprojecthd

Answer 1

@ha

Answer 2

Folding occurs when a stack of flat surfaces, are bent or curved as a result of permanent deformation. Therefore I'd say A
Here's a good link:
http://www.geography4kids.com/files/earth_faulting.html