A nurse assessing a toddler who is 18 months of age. Which of the following developmental milestones should the nurse expect the toddler to demonstrate?

A. Asking "who, what, where, and why" questions typically occurs around age 3 to 4 years. B. Following one-step directions is typically seen earlier, around 12 to 15 months. C. Recognizing items in a picture book is more characteristic of a 12-month-old child. D. By 18 months, toddlers often begin to combine two words, such as "want cookie" or "go outside."