The correct option is D Both A and C
Gamma rays are used for sterilization of pharmaceutical products after their production as to prevention the growth of any microorganism that may be present in the product. It is also used for sterlization of food product to kill any harmful bacteria or other organism that are present in the food, it won't make the food radioactive. Gamma rays act as a ionising radiation and it will inhibit the growth of microorganism. So it can be used to sterilize culture media.
So, the correct answer is 'Both A and C'