The correct option is (a) Selman Waksman.
Explanation:
The term 'antibiotics' was first time used by SA Waksman in 1945. Antibiotics are the substances which are produced by microorganisms such as fungi or bacteria. These substances are harmful to the growth of other microorganisms, example of some of the antibiotics are penicillin, streptomycin, chloramphenicol, etc.