The nurse is interviewing a client who is currently under the influence of a controlled substance and shows signs of becoming agitated. Which measure should the nurse take first when caring for this client

A. Be aware of hospital security.
B. Communicate a scolding attitude to intimidate the client.
C. Use confrontation.
D. Express disgust with the client’s behavior.

建设工程债发生的最主要的依据是（）。

A.侵权

B.合同

C.不当得利

D.无因管理