What is the chain of action that must occur if a principal is attacked?

What is the chain of action that must occur if a principal is attacked?
A . Arm’s reach (immobilize attacker if within arm’s reach, otherwise cover the principal) Sound off (shout the weapon displayed and the direction, in relation to the principal, from which it is coming) Cover Evacuate
B. Protect the client from live fire
C. Move to vehicles
D. Contact Law Enforcement for assistance

Answer: A