Fine motor skills
Ans. D. Fine motor skills
Explanation: Failure of a child to reach several developmental milestones within the appropriate time may indicate a developmental delay and require further evaluation, while a child who is deficient in a single developmental goal is less likely to have a problem. At three years of age, children are expected to be able to play in parallel but not cooperatively (social}, climb stairs with alternating feet and ride a tricycle by operating the pedals (gross motor), speak in simple conversations identifying themselves by name and gender (language), and copy a simple shape on command (fine motor). The child described in the question stem, being unable to reproduce a straight line, has not reached the expected milestone in fine motor development.