This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Impoant Motor Milestones, Subject name: Pediatrics
Which of the following cannot be done by a 15 month child? 
Select and explain. 
A. Walking with suppo, B. Transfers objects from 1 hand to another, C. Builds tower of 2 cubes, D. Speaks three-word sentences
D: Speaks three-word sentences
Answer: D: Speaks three-word sentences 
Explanation: A child speaks 2 word sentences at 2 years and 3 word sentences at 3 years -walks with suppo 12 months onwards, -transfers objects at 7 months, -builds a tower of 2 cubes at 15 months