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 normal infant sits briefly leaning forward on her hands, reaches for and grasps a cube and transfer it from hand to hand. She babbles but can not wave bye–bye nor can she grasp objects with the finger and thumb. Her age is – \nSelect and explain. \nA. 4 months, B. 7 months, C. 10 months, D. 14 months', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]