Concept:HIV/AIDS spreads mainly through direct contact with infected body fluids like blood, semen, or vaginal fluids.
Explanation:Using unsterilized sharp objects such as needles, blades, or clippers can transfer infected blood into another person's bloodstream.
These objects may carry the HIV virus if they were previously used by an infected person.
Sitting close to a patient does not spread HIV because the virus does not travel through air.
Handshaking and sharing clothes are also safe because HIV cannot pass through unbroken skin or by casual touch.
Therefore, only contact with contaminated blood through shared sharp objects creates a real risk of infection.
Answer:A. the use of unsterilized sharp objects