Answer:
The reaction rate of the digestion helps in understanding which part of the digestive system having trouble in digestion especialy stomach and intenstine related.
It involves the fact that most of the enrgy or calories are get by the small intestine and also vitamins and minerals are absorbed by this part of the digestive system so if the small intestine is having problem the rate of digestion would be affected and and an individual could be malabosrbed.
If the problem lies in the stomach it might show some effects of a poor digestion, however the rate of digestion would be better than if the problem lies in the small intestine.
The answer is A:<span> Metamorphic rocks</span><span> may display two different grain sizes.</span> :)
I believe the best answer is C.