A nurse is caring for a young adult client who has major depressive disorder and has been found legally incompetent. The client requires informed consent for abdominal surgery. The nurse should recognize that which of the following people can consent to the surgery?

A. The psychiatrist does not automatically have authority to provide consent for nonpsychiatric procedures unless legally appointed as guardian. B. A client who has been declared legally incompetent cannot provide informed consent. C. An appointed legal guardian is authorized to make healthcare decisions for a client who has been declared legally incompetent. D. A friend does not have legal authority to provide consent unless formally designated as a healthcare proxy or guardian.