Match the following columns:

Column-$I$	Column-$II$
$(A)$ Physical barriers	$(1)$ Interferon
$(B)$ Physiological barriers	$(2)$ Leukocytes
$(C)$ Cellular barriers	$(3)$ Tears
$(D)$ Cytokine barriers	$(4)$ Skin

Immunity acquired after an infection is:

Lymphoid tissue is found in:

Which of the following is $NOT$ included in physiological barriers?

In an antibody,disulphide bonds are present . . . . . .
$i$. between two heavy chains
$ii$. between two light chains
$iii$. between the constant region of a light chain and the constant region of a heavy chain
$iv$. between antigen binding sites of both the heavy and light chains
$v$. between the variable region of a light chain and that of a heavy chain
Select the correct answer from the options given below.

Which of the following is an autoimmune disorder?