The answer is B. an ultrasound
I'd say keeping the T cell count high because these are the cells that fight viral infections (HIV is one of them).
Answer:

Hope it helped,
Happy homework/ study/ exam!
I kept seeing four styles, authoritarian, authoritative, permissive, uninvolved.
Answer:
Endothelial cells lining blood vessels have a glycocalyx to protect them from the sheer stress of blood flow, as well as to aid in cell attachment that helps the immune system and blood clotting. ... Bacteria also have a glycocalyx which can create large colonies of bacteria known as a biofilm.
Explanation:
I hope it helped you