Final answer:
The agent should inform the buyer that asking about someone's HIV or AIDS status is a violation of privacy and is inappropriate.
Step-by-step explanation:
The agent's response should be to inform the buyer that asking about someone's HIV or AIDS status is a violation of their privacy and is inappropriate. HIV is a blood-borne, sexually transmitted disease, and it cannot be acquired through casual contact.
It is important to treat people with HIV/AIDS with respect, support, and understanding, rather than stigmatizing them or discriminating against them based on their health status.