Technician A says that when using an impact wrench to remove a bolt from the front of an engine's crankshaft, the crankshaft must be held to keep it from turning. Technician B says that when using an impact wrench to remove lug nuts on a raised vehicle, the brakes must be applied. Who is right?

a. Technician A
b. Technician B
c. Both A and B
d. Neither A nor B