Final answer:
The nurse should ask the client about her alternative methods of health care to get direct and accurate information, respecting the patient's confidentiality and autonomy.
Step-by-step explanation:
The best person to ask about the alternative methods of health care that a 45-year-old female client uses would be c. The client herself. This ensures that the information obtained is directly from the source and respects the patient's confidentiality and autonomy. Directly speaking with the client also allows the nurse to assess the patient's understanding and beliefs about her health, which is crucial in developing an effective and holistic care plan.