Which of the following contains the highest concentration of antibodies?

$A$ boy happens to put his foot on a rusted nail and the doctor gives him an injection. Most likely,what has the doctor administered?

Interferons were first discovered from cells infected with which of the following?

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

Which of the following is $NOT$ included in innate immunity?

Read the given statements carefully and identify the incorrect statements.
$(1)$ In active acquired immunity,antibodies are directly injected into the body.
$(2)$ Vaccination is considered under passive acquired immunity.
$(3)$ The human body distinguishes between self and non-self with the help of $Tc$ cells.
$(4)$ Innate immunity consists of four types of barriers.