When can a Driving Instructor legally allow a student to drive without supervision?

Answer: B — When they possess a valid driver's license

A driving instructor can legally allow a student to drive without supervision only when the student possesses a valid driver's license. This requirement is crucial because the law mandates that any individual operating a vehicle must hold a valid license to ensure that they have met necessary criteria for safe driving. Classroom instruction completion does not suffice, as no practical driving experience has been provided at that point; similarly, an instructor's confidence in a student's ability does not equate to legal permissions. Finally, while practical exams may allow for some form of assessment, they typically are conducted under the supervision of an examiner, and a student is not considered fully licensed until they have passed such assessments and obtained the official documentation. Therefore, having a valid driver's license is the key legal criterion for driving without supervision.