Which of the following eating disorders is characterized by extreme thinness, the pronounced fear of becoming fat, and exhibiting endocrine difficulties?

A) Anorexia nervosa
B) Bulimia nervosa
C) Binge eating disorder
D) Eating disorder not otherwise specified
E) Purging

Anorexia nervosa is characterized by extreme thinness, an intense fear of gaining weight or becoming fat, and potential endocrine difficulties such as amenorrhea (loss of menstruation), low testosterone levels, and disrupted thyroid function. Binge eating disorder involves consuming large amounts of food in a short period of time, often accompanied by feelings of guilt, shame, and loss of control. Bulimia nervosa involves recurrent episodes of binge eating, followed by compensatory behaviors such as purging or excessive exercise. Eating disorder not otherwise specified refers to eating disorders that do not meet specific diagnostic criteria for anorexia nervosa, bulimia nervosa, or binge eating disorder. Purging refers to the regular use of behaviors like self-induced vomiting, laxative or diuretic abuse, or excessive exercise as a means of compensating for food intake.