When is the World $AIDS$ Day celebrated?

The correct option is D $1^{st}$ December
$AIDS$ or Aquired ImmunoDeficiency Syndrome is a fatal sexually transmitted disease that is caused by the Human Immunodeficiency Virus $\left(HIV\right)$.

Apart from being sexually transmitted, it can also be transmitted via other modes of coming in contact with the body fluids of an infected person such as sharing of syringes or surgical instruments, from mother to child during birth, etc.

$HIV$ infects and destroys helper $T-$lymphocytes and macrophages in the human body which weakens the immune system.

World $AIDS$ day is celebrated on $1^{s}t$ December in order to raise awareness about $HIV$ infection and prevention measures of $AIDS$.