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: Pathology
Obesity with mental retardation is seen in ? 
Select and explain. 
A. Prader-Willi syndrome, B. Turner syndrome, C. Fragile-X syndrome, D. Noonan syndrome
A: Prader-Willi syndrome
Answer: A: Prader-Willi syndrome 
Explanation: Ans. is 'a' i.e., Prader-Willi syndrome Prader-Willi syndrome is characterized by : Mental retardation Sho stature Hypotonia Obesity Hyperphagia Small hands and feet Hypogonadism.