Jill Has Been in Treatment for Anorexia Nervosa for the Past

Jill has been in treatment for anorexia nervosa for the past two months. Over this time, she has gained weight to the point where her weight is in the average range for a woman of her height. The fact that she gained weight fairly quickly in treatment means

A) her prognosis for a full recovery is very good.
B) she is probably in need of little if any more treatment.
C) she has completed the most difficult part of her treatment.
D) little in terms of how likely she is to be successful in the long term.