Which of the following components is not included as an antibody?

Cells like neutrophils and monocytes play an important role in which process?

Cytotoxic $T$-cells are . . . . . . .

$A$: Live attenuated vaccine is better in terms of immunity provided to the recipient.
$R$: As secondary lymphoid organs,example $Peyer's$ patches are stimulated to protect the individual.

Select the $INCORRECT$ pair with respect to substances produced by cells involved in immune response.

Which cells secrete interferons?