I believe the answer is: Eat a well-balanced diet to increase energy and immunity
Even though physical activities improve both our energy and immunity in the long run, they are not as significant as maintaining well balanced diet in your life.
You need to make sure that you get your nutrients from various source of non-processed food in order to fulfill both your macronutrients and micronutrients.
Depending on the person, and the intake amount of course. But this can vary in many ways
I think the best response to this question would be
D. speak your mind
