Edward jenner:
created a treatment for rabies
studied cholera and anthrax in animals
made a smallpox vaccine from the cowpox virus
discovered how natural immunity worked

Edward Jenner is known as, “the father of Immunology.” He was an English physician and scientist that made a smallpox vaccine from the cowpox virus. This is known to be the world’s first vaccine and this discovery is said have saved more lives than the work of any other human being. Because of his work, World Health Organization declared smallpox an eradicated disease in the 1979. Up to the year 2002, Jenner was still being recognizes in the field of contemporary immunology and was even included in the list of 100 Greatest Britons. 

The answer is a. i hope this