The correct option is (a) Edward Jenner.
Explanation:
Passive immunity was first discovered by Edward Jenner against chickenpox.
In passive immunity readymade antibodies (y-globulins) obtained from human or animal serum, who already had recovered from an infectious ***, are injected into human body to develop immunity.
It is used against measeles, rubella, mumps, diphtheria, tetanus, snake venom, scarlet fever, rabies and Salmonella and many other bacterial infection.
