This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Social and Language Milestones, Subject name: Pediatrics
A child can laugh aloud at the age of:- 
Select and explain. 
A. 2 months, B. 4 months, C. 6 months, D. 9 months
B: 4 months
Answer: B: 4 months 
Explanation: A child laughs aloud at the age of 4 month. 1 month - ales to sound 2 months - Vocalizes 3 months - Coos 4 months - Laughs aloud