Final answer:
The best course of action for the nurse manager is to escalate the issue by reporting the maintenance department's unresponsiveness to the nursing supervisor to ensure a safe and efficient workplace.
Step-by-step explanation:
The nurse manager has already tried multiple times to get the broken electrical receptacle fixed through the proper channels. Given the lack of response and the increased workload it causes for the staff, the most appropriate next step would be to escalate the issue by reporting the unresponsiveness of the maintenance department to his or her nursing supervisor. This is because the supervisor has the authority and responsibility to ensure that the nursing environment is safe and efficient, and they may have more leverage over the maintenance department. Additionally, maintaining a safe environment is a crucial part of the everyday process in healthcare settings, and a faulty electrical outlet could pose safety risks. Option C is, therefore, the best course of action to take at this point.