A Parent Says to a Nurse, "How Do You Know

A parent says to a nurse, "How do you know when my child needs these screening tests the doctor just mentioned?" Which response by the nurse is the most appropriate?

A) "Screening tests are administered at the ages when a child is most likely to develop a condition."
B) "Screening tests are done in the newborn nursery and from these results, additional screening tests are ordered throughout the first two years of life."
C) "Screening tests are most often done when the doctor suspects something is wrong with the child."
D) "Screening tests are done at each office visit."