Interferons are synthesized in response to the infection of which of the following?

Which of the following is very important for maintaining good health?

$A$: $ELISA$ is based on the principle of antigen-antibody interaction.
$B$: In $ELISA$,infection by a pathogen can be detected by the presence of antigens or by detecting the antibodies synthesized against the pathogen.

Pus is a mixture of . . . . . . .
$I$ - dead neutrophils $\quad$ $II$ - dead microbes
$III$ - damaged tissues $\quad$ $IV$ - reticulocytes
$V$ - megakaryocytes

What precautions are required in case of airborne diseases such as pneumonia and the common cold?

What is a disease? What are the further classifications of disease?