Edward Genner discovered ‘vaccine’ in___________?

Edward Genner discovered ‘vaccine’ in___________?A. 1796
B. 1978
C. 1686
D. 1933

On May 14, 1796, Jenner took fluid from a cowpox blister and scratched it into the skin of James Phipps, an eight-year-old boy. A single blister rose up on the spot, but James soon recovered. On July 1, Jenner inoculated the boy again, this time with smallpox matter, and no disease developed. The vaccine was a success.