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
Heller's syndrome is characterized by regression of milestones after _________ 
Select and explain. 
A. 1 year, B. 2 years, C. 3 years, D. 6 months
B: 2 years
Answer: B: 2 years 
Explanation: Heller's syndrome (childhood disintegrative disorder) is characterized by normal development till the age of 2 years. After which there is loss of social, motor & language skills.