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': 'A child speaks sentences at the age of? \nSelect and explain. \nA. 6 months, B. 1 year, C. 18 months, D. 2 years', 'role': 'user'}, {'content': 'Answer: D \nExplanation: LANGUAGE MILESTONES: 1 month: Ales to sound. 2 months: responds to sound by stale or quietening to a smooth voice. 3 months: Coos (musical vowel sounds). 4 months: Laughs loud. 6 months: Monosyllables (ba, da), ah-ghoo 9 months: Understands spoken words, speaks bisyllables. 12 months: 1-2 words with meaning. 18 months: a vocabulary of 8-10 words. Can name one pa of the body. 2 years: 2-3-word sentences 3 years: Asks questions, knows full name and gender. 4 years: Says song or poem, tells a story, knows three colors. 5 years: Asks the meaning of words. Ref: Ghai Essential Pediatrics, ninth edition, pg. no. 49.', 'role': 'assistant'}]