The correct option is D Penicillium
Alexander Flemming, while working on Staphylococci bacteria, once observed a mould growing in one of his unwashed culture plates around which the bacteria, Staphylococci could not grow. He found out that it was due to a chemical produced by the mould and he named it Penicillin after the mould Penicillium notatum. However, its full potential as an effective antibiotic was established much later by Ernest Chain and Howard Florey. This antibiotic was extensively used to treat American soldiers wounded in World War II.