Vaccines produce–

Correct option is B

Sol. Vaccines produce active immunity by stimulating the body to produce antibodies and memory cells against a specific pathogen without causing the disease. This form of immunity takes time to develop but is long-lasting and helps the body respond faster upon real infection. Common vaccines include those for polio, measles, and hepatitis B.
Explanation of each option:
· (a) Natural immunity – Acquired through direct infection with the disease-causing organism. Vaccines mimic infection but don’t qualify as "natural."
· (b) Active immunity – Correct Answer. Involves stimulation of the immune system to produce a defensive response. This can be naturally acquired (through infection) or artificially induced (through vaccination).
· (c) Passive immunity – Provided by transferring ready-made antibodies (e.g., from mother to baby or via immunoglobulin injections). Does not involve vaccines.
· (d) Acquired immunity – A broader category that includes both active and passive immunity. The question specifically refers to the process initiated by vaccines, which is active.