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: Pediatrics
[{'content': 'A normally growing child smiles back (social smile) at the following age \nSelect and explain. \nA. 6-8 weeks, B. 4-6 weeks, C. 2-4 weeks, D. 6-10 weeks', 'role': 'user'}, {'content': 'Answer: A \nExplanation: SOCIAL AND ADAPTIVE MILESTONES:\n2 months: social smile(smile after being talked to).watches mother when spoken to and may smile.\n3 months: Recognizes mother, anticipates feeds.\n4 months: Holds rattle when placed in hand and regards it. Laughs aloud. Excited at the sight of food.\n6 months: recognizes strangers, stranger anxiety. Enjoy watching own image in the mirror, shows displeasure when toy pulled off.\n9 months: waves bye bye\n12 months comes when called, plays a simple ball game. kisses the parent on request. Makes postural adjustments for dressing.\n15 months: jargon, starts imitating mother.\xa0\n18 months: copies parents in tasking, dry by day, call mother when he wants potty, points to three parts of the body on request.\n2 years: ask for food, drink, toilet, pulls people to show toys.\n3 years: shares toys, know full name and gender, dry by night.\n4 years: Plays cooperatively in a group, goes to the toilet alone, washes face, brushes teeth. Roleplay.\n5 years helps in the household task, dresses, and undresses', 'role': 'assistant'}]