This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Medicine
[{'content': 'Obesity is ordinarily associated with low ghrelin levels. The example of a condition where obesity associated with high ghrelin level is: \nSelect and explain. \nA. Hypothyroidism, B. Prader willi syndrome, C. Hypoadrenalism, D. Insulinoma', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ghrelin is an 28 aa peptide produced from stomach. It increases food intake and promotes weight gain. It serves as a signal for initiation of feeding. It inversely corelates with BMI. In obesity ghrelin level are low. EXCEPTION is Prader willi syndrome a genetic obesity syndrome characterized by severe hyperphagia, growth hormone deficiency, hypogonadism. The hyperphagia is due to increased circulating Ghrelin levels. Ref: Sleisenger and Fordtran's, Edition-9, Page-8.", 'role': 'assistant'}]