Match List-I with List-II:

List-I	List-II
Types of barriers	Examples
(A) Cytokine barriers (B) Physical barriers (C) Cellular barriers (D) Physiological barriers	(I) Mucus coating (II) Tears from eyes (III) Phagocytosis (IV) Interferons

Choose the correct answer from the options given below:

The correct option is (A)- (IV), (B)- (I), (C)- (III), (D)- (II).

Let us understand the classification of different barriers in the innate immune system step-by-step to explain why this matching is correct:

1. (A) Cytokine barriers matches with (IV) Interferons
Cytokine barriers consist of specialized proteins secreted by cells to protect other non-infected cells. Interferons are glycoproteins secreted by virus-infected cells. They act as cytokines, signaling neighboring healthy cells to trigger antiviral defenses and prevent the replication and spread of the virus. Therefore, (A) matches with (IV).

2. (B) Physical barriers matches with (I) Mucus coating
Physical barriers prevent the entry of micro-organisms and foreign pathogens into the body. The mucus coating lining the respiratory, gastrointestinal, and urogenital tracts acts as a physical trap for microbes, preventing them from penetrating deeper tissues. Therefore, (B) matches with (I).

3. (C) Cellular barriers matches with (III) Phagocytosis
Cellular barriers involve specific types of cells that identify and destroy invading pathogens. Phagocytic cells (such as macrophages and neutrophils) engulf and digest foreign particles, cellular debris, and microbes through the process of phagocytosis. Therefore, (C) matches with (III).

4. (D) Physiological barriers matches with (II) Tears from eyes
Physiological barriers involve chemical secretions and body conditions that inhibit the growth of pathogens. Tears from the eyes contain antibacterial enzymes (like lysozyme) and wash away foreign particles, acting as a physiological defense mechanism. Therefore, (D) matches with (II).

By compiling the matches together, we get:
(A) - (IV)
(B) - (I)
(C) - (III)
(D) - (II)