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
A	severely	incapacitating disturbance of	mental and
emotional development that causes problem in learning,
communication, and relating to others is 
Select and explain. 
A. Autism, B. Learning disability, C. Mental retardation, D. Dyslexia
A: Autism
Answer: A: Autism 
Explanation: None