Answer: b) the fault locks, and stress builds up until an earthquake occurs
Step-by-step explanation:
The earthquake occurs at the site of fault. A fault can be defined as a fracture and it divides a rock or earth crust into two parts in between a fracture or crack develops. The fault causes the rock or the separated parts of the earth crust to slide past each other resulting in the form of earthquake. Due to stress created the earth outer layer pushes the two sides of the fault to move towards each other. This leads to the development of friction between the two surfaces slide past each other. The energy so produce due to this frictional movement causes the earth crust to shake resulting in earthquake.