As an energy source, To heal and build and repair tissue, To sustain growth, To help transport oxygen to the cells, To regulate body functions. hope this helped :)
It D all of the above or B. conflict resolution skills
It could be due to stress. Everyone deals with stress differently. Usually they are mad at themselves, like they have failed at supporting and that can lead to depression also.
Umm I Kinda Do Understand But I Am Not Sure Really