A registered nurse who usually works on a medical-surgical unit is told to report to the cardiac care unit (CCU) for the day because the CCU is short staffed and needs additional help to care for the clients. The nurse has never worked in the CCU. Which of the following responses is the most appropriate nursing action ？（）
A．Call the hospital lawyer.
B．Report to the CCU and identify tasks that she feels she can safely perform.
C．Speak to the nursing supervisor.
D．Refuse to go to the CCU.