What is the best description of anorexia nervosa?

A) Occurs most frequently in adolescent males
B) Occurs most frequently in adolescents from lower socioeconomic groups
C) Results from a posterior pituitary disorder
D) Results in severe weight loss in the absence of obvious physical causes

The etiology of anorexia remains unclear, but a distinct psychological component is present. The diagnosis is based primarily on psychological and behavioral criteria. Females account for 90% to 95% of the cases. No relation has been identified between socioeconomic groups and anorexia. Posterior pituitary disorders are not associated with anorexia nervosa.