Which virus undergoes rapid mutation?

How many types of enzymes are present in the core protein of the $HIV$ virus?

The cause of $AIDS$ is ..........

$HIV$ causes a reduction in:

How many of the following statements regarding the transmission of $AIDS$ are correct?
$(a)$ $AIDS$ is transmitted by using the belongings of an infected person.
$(b)$ It can be transmitted through organ transplantation.
$(c)$ It can be transmitted through blood donation.
$(d)$ It can be transmitted from mother to child through the placenta.
$(e)$ It spreads through droplet infection via sneezing and coughing.
$(f)$ It is transmitted from a breastfeeding mother to her child.
$(g)$ It can be transmitted through the saliva of a patient.

The first case of $AIDS$ in India was reported in: