A 20 year old girl with amenorrhea and BMI of 14 still thinks she has to lose weight. What is the most likely diagnosis?

The key is A. Anorexia nervosa. [Anorexia nervosa, often referred to simply as anorexia, is an eating disorder, characterized by low weight, food restriction, fear of gaining weight, and a strong desire to be thin. Many people with anorexia see themselves as overweight even though they are, in fact, underweight].