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
All are feature of Autistic disorder EXCEPT:March 2013 (b) 
Select and explain. 
A. 75% mentally retarded, B. Usually appears by 2-3 years of age, C. Absent social smile, D. Third person hallucination
D: Third person hallucination
Answer: D: Third person hallucination 
Explanation: Ans. D i.e. Third person hallucinationAutismDifficulty in concentration and communication,Lesion in frontal and temporal lobe and cerebellum,Delayed speech and language development,Problems in forming social relationships in early childhood,Stereotyped movements,Poor speech,Lack of social interaction,