Match the following:

Correct option is C

Acid in the stomach, saliva in the mouth, tears from eyes, all prevent microbial growth and are physiological barriers. Skin on our body is the main barrier which prevents entry of the micro-organisms. It is a physical barrier. Certain types of leukocytes (WBC) of our body like polymorpho-nuclear leukocytes (PMNL-neutrophils) and monocytes and natural killer (type of lymphocytes) in the blood as well as macrophages in tissues can phagocytose and destroy microbes. Virus-infected cells secrete proteins called interferons which protect non-infected cells from further viral infection. They are cytokine barriers.