Which of the following motor skills is typical for a 3-year-old child?

A 3-year-old child typically exhibits the ability to wiggle their thumb, showcasing the development of fine motor skills and hand-eye coordination that is common at this age. At around three years old, children are refining their ability to control their fingers and hands, which allows them to engage in various activities, such as drawing, manipulating small objects, and performing simple tasks that involve grasping.

In contrast, the other options involve more advanced gross motor skills that are not typically fully developed until later ages. For example, performing a cartwheel generally requires greater coordination, body control, and strength, which a child usually begins to master around age 5 or 6. Skipping on one foot also reflects a higher level of motor coordination and balance that develops in preschool-age children, generally becoming apparent between the ages of 4 and 6. Balancing on one foot for 10 seconds is a skill that tends to emerge around age 4, indicating further development of balance and stability, which is less common in a 3-year-old. Thus, the ability to wiggle the thumb accurately represents the motor skill development expected in a child of this age.