A nurse enters the hallway and discovers a visitor looking at a client's medical information on a computer. Which of the following actions should the nurse take first?

The correct answer is D: Inform the visitor that client records are confidential. This is the first action the nurse should take because it directly addresses the breach of confidentiality and educates the visitor on the importance of privacy. By informing the visitor about the confidentiality of client records, the nurse helps prevent further unauthorized access and potential harm to the client. Closing the documentation program (choice A) or finding out which staff member left it open (choice B) are not immediate actions to address the current breach. Informing the charge nurse (choice C) can be done after addressing the visitor.