OK well first of all I hate biology but I like writing so you can use :: The molecular reactions of cellular respiration transform Krebs cycle into the more readily available bond energy of ATP.
In order to produce an effective immune response within the body, the person must be injected with a dosage of a virus or bacteria, and for it to be allowed to grow in the person, which replicates just enough to stimulate a response from the immune system.
I might be wrong but i think is C
The correct answer is plants