An antibody molecule is represented as:

Match the following columns:

Column-$I$	Column-$II$
$1.$ Saliva and tears	$a.$ Cytokine barrier
$2.$ Mucus coating	$b.$ Cellular barrier
$3.$ $PMNL$	$c.$ Physiological barrier
$4.$ Interferons	$d.$ Physical barrier

Active immunity is associated with:

When is the immune response most intense?

The function of a vaccine is the production and storage of

Given below are two statements. Select the most appropriate answer from the given options.
Statement-$I$: $T$-lymphocytes have $4$ subtypes as helper,killer,memory,and suppressor $T$-cells.
Statement-$II$: $B$-lymphocytes mature in the thymus and are responsible for cell-mediated immunity.