Answer:
D. Digestion
Digestion does not affect your ability to exercise and work out. It does not affect the efficiency of your work. With muscle movement, this is important because if you don't have good muscle movement, then you can't do activities in their respectable times and you might also not have a good reaction time. With type of movement, different people have different ranges of motion and different ways of which they do certain activities, and the type of movements you're doing to accomplish these activites plays a vital role in the efficiency of the movement. Then metabolism, this is probably the most important one because it's essentially chemical reactions that happen in your body to keep you alive. Without good metabolism, you're typically a lot slower at pretty much everything. Digestion does not play a role in your efficiency.