A nurse collects data from a child descending stairs by placing both feet on each step and holding on to the railing. The nurse should understand that these actions are developmentally appropriate at which of the following ages?

A. 6 years: By age 6, most children can walk down stairs alternating feet without needing to hold a railing. Using both feet on each step at this age may indicate a developmental delay in gross motor skills. B. 3 years: At 3 years old, it is typical for a child to descend stairs using both feet on each step while holding the railing for balance. This reflects age-appropriate coordination and muscle strength. C. 4 years: Most 4-year-olds begin to alternate feet when descending stairs, showing improvement in balance and leg strength. Using both feet on each step would be more typical for a younger child. D. 5 years: By age 5, children typically master alternating feet going up and down stairs without assistance. Using both feet on each step would not align with expected motor development at this stage.