A client asks the nurse what PSA is. The n
题型：单项选择题
问题：
A client asks the nurse what PSA is. The nurse should reply that it stands for
A．prostate-specific antigen, used to screen for prostate cancer.
B．protein serum antigen, used to determine protein levels.
C．pneumococcal strep antigen, a bacteria that causes pneumonia.
D．papanicolaou-specific antigen, used to screen for cervical cancer.