The correct option is C Alexander Fleming, Penicillin
In 1928, a Scottish researcher named Sir Alexander Fleming is credited with discovering penicillin. Fleming was experimenting with the influenza virus at the time. When Fleming returned from a two-week vacation, he discovered a mould on a Staphylococcus culture plate that had been accidently infected. When he looked at the mould, he observed that the culture stopped Staphylococci from growing. The colony was characterised by Fleming as a "fluffy white mass that rapidly grows in size and sporulates" after a few days, changing colour from dark green to black to bright yellow.