This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Microbiology
[{'content': 'A child can make a 3 cube tower at the age of \nSelect and explain. \nA. 36 months, B. 15 months, C. 20 months, D. 24 months', 'role': 'user'}, {'content': 'Answer: B \nExplanation: At 15 monthsMotor: Walks alone; crawls upstairs.Adaptive: Makes the tower of 3 cubes; makes a line with crayon; inses raisin in the bottle.Language; Jargon; follows simple commands; may name a familiar object (e.g. ball).Social: Indicates some desires or needs by pointing; hugs parents.', 'role': 'assistant'}]