Eating disorders are caused by all of the following factors EXCEPT:
A psychological factors
B. genetic factors
C economic class
D. financial factors
Please select the best answer from the choices provided.

The person who utilize the progression principle will keep adding the difficulty of the exercise that he's doing, while the person who does not, will only stay stagnant.  the person that utilize progression principle, will get a stronger endurance because now his body is conditioned to do harsher routines.{the answer was already on verified)