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
Methylphenindate is drug of choice for: 
Select and explain. 
A. Obsessive compulsive disorder, B. ADHD (attention deficit hyperkinetic disorder), C. Enuresis, D. Autism
B: ADHD (attention deficit hyperkinetic disorder)
Answer: B: ADHD (attention deficit hyperkinetic disorder) 
Explanation: None