If a person is breathing normally, which of the following could prevent him from using his body to exercise normally? a
not getting enough sunlight, because cells need sunlight to function

b
not getting enough sleep, because the body only makes energy for exercise while asleep

c
not eating enough food, because cells need molecules from both food and air to work

d
nothing, because he would be able to exercise normally as long as his cells are getting molecules from the air