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: Pharmacology
[{'content': 'Methylphenindate is drug of choice for: \nSelect and explain. \nA. Obsessive compulsive disorder, B. ADHD (attention deficit hyperkinetic disorder), C. Enuresis, D. Autism', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]