Match List-I with List-II. List-I List-II A. Mucus coating of the epi…

The correct answer is Option (2) → A-III, B-IV, C-I, D-II

(A) Mucus coating of the epithelium lining the respiratory tract — this matches (III) Physical barrier. Innate immunity gives barriers against the entry of microbes. Like the skin, the mucus physically traps microbes before they can enter the body.

(B) Saliva in the mouth — this matches (IV) Physiological barrier. Saliva, acid in the stomach and tears do not block microbes in their path. They prevent microbial growth.

(C) Rheumatoid arthritis — this matches (I) Autoimmune disease. Here the body attacks its own cells because of genetic and other unknown reasons.

(D) Colostrum — this matches (II) Passive immunity. Colostrum is the yellowish milk of the first few days. It carries ready-made antibodies (IgA) from the mother, so the baby does not make them itself.

NCERT Extract:
Innate Immunity – “… (i) Physical barriers : Skin on our body is the main barrier which prevents entry of the micro-organisms. Mucus coating of the epithelium lining the respiratory, gastrointestinal and urogenital tracts also help in trapping microbes entering our body. (ii) Physiological barriers : Acid in the stomach, saliva in the mouth, tears from eyes–all prevent microbial growth.”
Auto Immunity – “… Rheumatoid arthritis which affects many people in our society is an auto-immune disease.”
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.”