I believe that C would be the best answer to this question.
I really hope that this helps you out
Can you reword this question? It is confusing, but I'd love to help.
Internal response; when a person is infected by a bacteria or virus, the immune system springs into action to fight against the infections. Geotropism and phototropism are dealing with plants and they way they grow, while fight or flight is a physiological reaction by the human body in stressful situations-- so they are incorrect.
Answer:
All of the activities are directed by plant hormone