题目：
The nurse is caring for a client admitted to the emergency department after a motor vehicle accident. Under the law, the nurse must obtain informed consent before treatment unless
A. the client is mentally ill.
B. the client refuses to give informed consent.
C. the client is in an emergency situation.
D. the client asks the nurse to give substituted consent.
答案：
参考答案：C
解析：The law doesn’t require informed consent in an emergency situation when the client is unable to give consent and no next of kin is present. A mentally competent client may refuse or revoke consent at any time. Even though a client who is declared mentally incompetent can’t give informed consent, mental illness doesn’t by itself indicate that the client is incompetent to give informed consent. Although the nurse may act as a client advocate, the nurse can never give substituted consent.
