Which of the following is mismatched?

When a person produces antibodies in response to a pathogen entering the body,this type of immunity is called ..........

Which of the following acts as a physical barrier for immunity?

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.

Identify the cells that form a phagolysosome.

Cell-mediated immunity is mainly a function of