A client calls the physician’s office 2 days after a herniorrhaphy to report that his scrotum is swollen and painful. Which of the following instruction by the nurse could promote comfort for the client

A. Apply a snug binder on his abdomen.
B. Have him wear a truss to support the scrotum.
C. Have him lie on his side and place a pillow between his legs.
D. Elevate the scrotum and place ice bags on the area intermittently.

雷电防护设备有哪些，原理如何？