A Male Patient Asks, "Why Do I Have to Use

Multiple Choice

A male patient asks, "Why do I have to use another contraceptive? I had a vasectomy last week." The best response is

A) "A vasectomy is only 80% effective."
B) "A vasectomy is not effective in all men."
C) "Semen may contain sperm for 6 months following a vasectomy."
D) "Complete sterilization doesn't occur until all sperm have left the system."