What is a Bacille Calmette–Guérin (BCG)?

Correct option is C

Ans. (c)
Sol. BCG is a live attenuated vaccine derived from Mycobacterium bovis used to prevent tuberculosis, especially in children.
Explanation of each option:
· (a) Toxoid – Inactivated toxin used in diphtheria/tetanus vaccines.
· (b) Immunoglobulin – Antibody-based treatment, not vaccine.
· (c) Live attenuated vaccine – Correct answer. BCG is a weakened form of TB bacteria.
· (d) Killed vaccine – Contains dead organisms (e.g., polio-Salk).