A nurse is preparing to administer 0800 medications to a client. The medication administration record (MAR) states "phenobarbital" and the medication the pharmacy supplied is pentobarbital. Which of the following actions should the nurse take?

A. Check the client's MAR to see what the client received the day before: This does not address the issue of a potential medication error. B. Ask the client what medication she took yesterday: The client may not accurately recall medication names or dosages. C. Ask the client if she has any allergies: While important, this does not resolve the issue of the medication discrepancy. D. Check the prescription in the client's medical record: This is the most appropriate action to verify the correct medication.