Such person is at least 21 years of age and has passed the written and visual examinations required for obtaining a class C driver's license.

Such person has a valid driver's license which entitles the licensee to drive a motor vehicle in any class or classes.

Such person is at least 18 years of age and has passed the written and visual examinations required for obtaining a class C driver's license.

Such person has a valid driver's license which entitles the licensee to drive a motor vehicle in Class C.