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: Dental
Definition of AUTISTIC child is? 
Select and explain. 
A. Incapacitating communication and emotional problem, B. Most severly handicapping condition, C. Disorder in one or more psychological processes, D. Chronic recurrent and Paraxysmal changes in neurologic function
A: Incapacitating communication and emotional problem
Answer: A: Incapacitating communication and emotional problem 
Explanation: None