I think the answer is D, hope this helps you and have a great day!!!! :)
A chemical substance in food that helps maintain the body.
It may seem like it's a unit use to measure the energy value of food, but that's calories.
And "nutrients" is not a study of anything.
What is you trying to say
Answer by JKismyhusbandbae: withdrawal.
Why: When a person that is addicted to a drug, stops using that drug, they may demonstrate withdrawal symptoms.