In which of the following situations is $AIDS$ $NOT$ transmitted?

What is the correct sequence of events that occur after $HIV$ infection in a human body?
$(I)$ Viral $DNA$ enters the host $DNA$
$(II)$ Entry into $T_H$ lymphocytes and replication
$(III)$ Viral $RNA$ is converted into viral $DNA$ by reverse transcriptase
$(IV)$ $HIV$ enters into macrophages
$(V)$ Destruction of $T_H$ lymphocytes
$(VI)$ New virus particles are produced from the host cell

The spread of $AIDS$ occurs through.........

Provide the full forms of the following abbreviations:
$(i)$ $DNA$
$(ii)$ $AIDS$

$A$ doctor,while operating on an $HIV$ patient,accidentally cut himself with a scalpel. He comes to you,suspecting that he may have contracted the virus. Which test will you advise him to perform to rule out or confirm his suspicion?

What does '$A$' represent in the given figure?