What type of immunity is provided by the administration of antibodies after a snake bite?

Which of the following statements are correct regarding the structure and types of antibodies in humans?
$i$. Antibodies are also called Immunoglobulins that are produced as an immune response to antigenic stimulation.
$ii$. They are produced by all types of $T$-lymphocytes and $B$-lymphocytes.
$iii$. An antibody is a $Y$-shaped molecule formed of four polypeptide chains. Antibodies present in plasma determine many blood group systems like $ABO$,$Rh$,$P$,$MNS$ etc.
$iv$. An antibody molecule consists of two antigen-binding sites called paratopes.

Lysozyme present in perspiration,saliva,and tears,destroys:

Many microbial pathogens enter the gut of humans along with food. What are the preventive barriers to protect the body from such pathogens? What type of immunity do you observe in this case?

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

The lymphocytes provide the principal defence mechanism by producing