Final answer:
Transform boundaries experience shear stress, which occurs when rocks move horizontally past each other in opposite directions, causing them to deform and potentially forming faults.
Step-by-step explanation:
A transform boundary is a type of plate boundary where two tectonic plates slide past each other horizontally. This movement creates stress on the rocks at the boundary. The type of stress that occurs at a transform boundary is shear stress. Shear stress is the stress that is created when rocks move horizontally past each other in opposite directions. It causes rocks to deform and can result in the formation of faults, such as strike-slip faults.