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 boy can grasp a rattle & recently he become able to transfer objects, hand to hand. He can do _________ \nSelect and explain. \nA. Babble, B. Say 'mama' or dada, C. Sit without suppo, D. Stand with suppo", 'role': 'user'}, {'content': 'Answer: A \nExplanation: Child develops the ability to grasp a rattle and transfer from one hand to other by 6 months.So according to the options,by 6 months he is able to babble. Key language milestones: 1 mnth - Ales to sound 3mnth - coos(musical vowel sounds) 4mnth-laugh loud 6mnth-babble (monosyllables) 9 mnth-bisyllables(mama dada) 12mnth- 1-2 words with meaning 18mnth-8-10word vocabulary 2yr- 2-3 word sentences,uses pronouns"I","me","you 3 yr- asks questions;knows full name and gender 4yr-says song or poem,tells stories 5yr-asks meaning of words Ref : Essential pediatrics,op ghai, 8th edition Pg no:50,53 (tables:3.2,3.3,3.4)', 'role': 'assistant'}]