Which of the following is an autoimmune disease?

The immunity acquired by the fetus from the mother through the placenta or by the infant from mother's milk for a short period is known as:

Interferons are ...........

The treatment of snake-bite by antivenom is an example of

Match the following columns:

Column-$I$	Column-$II$
$P$. Physical barriers	$I$. Acid in stomach,saliva in mouth,tears from eyes
$Q$. Physiological barriers	$II$. Skin,mucus coating of epithelium lining the respiratory,gastrointestinal and urogenital tracts
$R$. Cellular barriers	$III$. Interferons
$S$. Cytokine barriers	$IV$. Polymorphonuclear leukocytes ($PMNL$-neutrophils),monocytes,$NK$ cells,macrophages

When is the immune response most intense?