Answer:
The correct answer is
A. Anxiety- Nervous system
Explanation:
Anxiety has nothing to do with the Nervous system; the nervous system is the nerves in your body and is not what makes you nervous or anxious. All the other answer choices are correct.
1. Small Intestines
2.Vitamins
Sorry i don’t know the others
It is important because the results would not be reliable since other variables you are not testing could have been in affect.
Hope this helps(;
