Alexa had a single sexual encounter with Jake about five years ago. Jake has just notified Alexa that he has tested positive for HIV. Which of the following may be true for Alexa?

A. She may be in the clinical latency stage of HIV infection but have no symptoms.
B. If she has not developed any symptoms of infection by now, it's unlikely she has HIV.
C. If it turns out that she is infected with HIV, there is little she can do now to protect her health.
D. She is certain to develop full-blown AIDS within the year if she does not begin medication.​