I would say Push up's for your answer because of balance.
The answer is A which is the second option
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.
Answer: Osteomyelitis
Explanation:
inflammation of the bone marrow and adjacent bone (oste/o means bone, myel means bone marrow, and -itis means inflammation).