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
[{'content': 'This milestone is achieved by a child at age of __________ \nSelect and explain. \nA. 2 months, B. 3 months, C. 4 months, D. 5 months', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Follows moving object (180degrees) develops at 2 months Also at 2 months Smiles on social contact Listens to voice and coos Head sustained in a plane of the body on ventral suspension Ref : Nelson 20th edition pg no : 66', 'role': 'assistant'}]