By the time they reach adulthood, most people can perform many different activities involving motor skills. Motor skills involve such diverse tasks as riding a bicycle, threading a needle, and cooking a dinner. What all these activities have in common is their dependence on precision and timing of muscular movement. This paragraph best supports the statement that

• most adults have not refined their motor skills.
• all adults know how to ride a bicycle.
• refined motor skills are specifically limited to adults.
• children perform fewer fine motor activities in a day than adults do.
• threading a needle is a precise motor skill.