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
Which of the following autistic spectrum disorder carries good prognosis? 
Select and explain. 
A. Childhood autism, B. Rett's disease, C. Heller's syndrome, D. Asperger's syndrome
D: Asperger's syndrome
Answer: D: Asperger's syndrome 
Explanation: Asperger's syndrome is characterized by impaired social interaction and stereotyped behavior but no intellectual disability and no language disturbances,hence carries good progrosis.