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 hallucination Autism Difficulty 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,