Answer: Option A
Step-by-step explanation:
An experiment was performed in which a bacterial population was inoculated in the glucose-salt agar penicillin and another on the nutrient agar containing penicillin.
Both of the plates that contains bacteria have penicillin mutant bacteria. This is so because both the plates contains penicillin, there was growth seen on both the plates.
On one plate the bacteria have grown with no histidine( his mutant) and on another using the nutrient agar.
So, the colonies on the both the medium is penicillin-resistant mutant.