Why Did Alexander Fleming Suspect He Could Get Penicillin from a Species

Why did Alexander Fleming suspect he could get penicillin from a species of mold?

A) Soldiers drinking fermented alcohol were less likely to have bacterial infections.
B) Bacteria on culture plates were unable to grow near mold contamination.
C) Wounds with superficial mold on the bandages were not becoming septic.
D) Soldiers eating moldy bread were not suffering from wound infections.
E) Patients infected with a fungus like, athlete's foot, were less likely to have bacterial infections.