Identify the antibody present in colostrum.

The correct answer is Option (1) → IgA

Option (1) IgA — Correct. Colostrum, the yellowish milk produced in the first few days after birth, has several antibodies, mainly IgA. These protect the newborn baby; this is an example of natural passive immunity.

NCERT Extract:
Active and Passive Immunity – “When ready-made antibodies are directly given to protect the body against foreign agents, it is called passive immunity. … The yellowish fluid colostrum secreted by mother during the initial days of lactation has abundant antibodies (IgA) to protect the infant. The foetus also receives some antibodies from their mother, through the placenta during pregnancy. These are some examples of passive immunity.”