A client on an inpatient psychiatric unit at a community mental health center is pacing up and down the hallway. The client has a history of aggression. Which response by the nurse would be best when approaching the client ？（）
A．"If you can't relax, you could go to your room. "
B．"Would you like your antianxiety medication now "
C．"You're pacing. What's going on "
D．"Let's go play a game of pool. "