Hm. I believe it may be false but I may be incorrect.
Answer: This experiment has two factors.
Explanation:
This experiment has two factors in it. These two factors are: One is normal/ vegetarian diet and other is unrestricted /restricted salt diet.
The condition that is kept in the experiment are kept varying and the results are recorded in order to check whether vegetarians can lower blood pressure by their diet or not.
So, here in the experiment there are two factors on which the experiment is based on.
Actually, any mental illness can turn into a disability depending on how bad it gets, if someone has anxiety, they could never leave the comfort of their own home. Schizophrenia ,Cognitive Dysfunction is all i know of.