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': 'By what age does a child achieve the following developmental milestone? \nSelect and explain. \nA. 5 months, B. 6 months, C. 8 months, D. 9 months', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Age\n\n\nMilestones\n\n\n\n\n\n\n4 months\n6 months\n9 months\n10-12 months\n12 months\n\n\nBidextrous grasp\nUnidextrous / palmar grasp(Ulnar grasp)\nImmature Pincer grasp\nPalmar grasp (Radial grasp)\nMature Pincer grasp', 'role': 'assistant'}]