A child presents for a well check. They can sit on a small chair, walk up stairs with one hand held, and make a tower with four cubes. They can name pictures and has a vocabulary of about ten words. They kiss their parents with a pucker and can feed themself. If they are developing as expected, how old are they most likely to be? A. 12 months old B. 15 months old C. 18 months old D. 24 months old