A nurse is preparing to administer medication to a client and discovers that a nurse on the previous shift gave the client a wrong dose of the medication. Which of the following actions should the nurse take?

The correct answer is B: File an incident report within 24 hr. This is the most appropriate action as it ensures proper documentation of the medication error, which is crucial for tracking and analyzing incidents to prevent future occurrences. It also follows standard protocols for reporting medication errors promptly. Calling the nurse who made the error (choice A) may be necessary later, but the immediate priority is to document the incident. Notifying the pharmacist (choice C) is important, but filing an incident report is the primary step. Placing an incident report in the client's record (choice D) is important, but it should be accompanied by filing a formal report as per protocol.