Psychoneuroimmunology studies the effects of stress on the immune system. Identify the correct statements describing its working:

(A) The Leucocytes within the immune system identify and destroy antigens such as viruses
(B) Stress does not affect natural killer cell cytotoxicity
(C) Stress leads to the production of antibodies
(D) There are several kinds of Leucocytes including the T cells, B cells and natural killer cells
(E) D-cells produce antibodies

Choose the correct answer from the options given below:

(A), (C) & (D) only

The correct answer is Option (3) → (A), (C) & (D) only

Explanation:

• (A) The Leucocytes within the immune system identify and destroy antigens such as viruses: This statement is correct. Leucocytes (white blood cells) play a crucial role in identifying and attacking pathogens like viruses.
• (B) Stress does not affect natural killer cell cytotoxicity: This statement is incorrect. Stress can affect natural killer cell cytotoxicity, which is of major importance in the defence against various infections and cancer.
• (C) Stress leads to the production of antibodies: This statement is correct. Stress can stimulate the immune response, leading to antibody production, although chronic stress may impair immune function overall.
• (D) There are several kinds of Leucocytes including the T cells, B cells and natural killer cells: This statement is correct. These are key types of leucocytes involved in the immune response.
• (E) D-cells produce antibodies: This statement is incorrect. B cells, not D cells, are responsible for antibody production.