Emily,who Is Always Slightly Depressed,helps a Child Find Its Mom

Emily,who is always slightly depressed,helps a child find its mom at the mall.Emily is surprised to find her mood has improved.This is likely because

A) helping a person often relieves a negative mood.
B) helping a person can lead to a reward.
C) empathy led Emily to help the child.
D) the child was able to articulate how much he was helped.
E) the child's mom was not a relative of Emily's.