A Client Was Clearly Very Relieved When an HIV Test

A client was clearly very relieved when an HIV test came back negative."Thank goodness.I've had sex several times without a condom,and when one of my friends said he was sick,I think I panicked." Which of the following would be most important to emphasize to the client immediately?

A) Abstinence is the only way to be certain you are HIV-free.
B) Sex should be restricted to one partner.
C) The test could be wrong and the client might still have an HIV infection.
D) The test would not cover any recent infection, so if the client has had recent unprotected sex, the test should be repeated in 3 months.