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: Psychiatry
A 13 years old boys is often aggressive, arguing with parent and teachers. He has history of frequent lying and stealing money at home. He always runs away from class to play. The diagnosis is- 
Select and explain. 
A. Conduct disorder, B. Oppositional defiant disorder, C. Autism, D. Pervasive developmental disorder
A: Conduct disorder
Answer: A: Conduct disorder 
Explanation: Ans: A. Conduct disorder(Ref: Kaplan & Saddock's th/e p. 1139).Conduct disorder is characterized by a persistent and significant pattern of conduct in which the basic rights of others are violated or rules of society are not followed.The onset occurs much before 18 years of age, usually even before pubey.The characteristic clinical features include: -Frequent lyingStealing or robberyPhysical violence like rape, fire setting, assault, use ofweapons, fighting and aggresiveness.Running away from home and school - Therefore, backward in studies.