This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Growth and development, Subject name: Pediatrics
This social milestone is established by age of ___________ 
Select and explain. 
A. 1 month, B. 2 months, C. 3 months, D. 4 months
B: 2 months
Answer: B: 2 months 
Explanation: Babies establish a smile on social contact by 2 months. Also done at 2 months Head sustained in a plane of the body on ventral suspension Follows moving object by 180 degrees Smiles on social contact Listen to voices and coos Ref : Nelson 20th edition pg no : 67