Answer: A most probably
Step-by-step explanation:
In B, HAART doesn't slow the growth it just doesn't let the infections take place as often as they do when the immune system is weak. In C, I'm quite unsure but I don't think you can prevent aids like that. AiDS is controlled if spotted initially but not prevented. And in D, it's a viral disease so antibiotics will have no affect because they treat bacteria related diseases. So we are left with A.