When is a learner's permit holder allowed to drive without supervision?

The appropriate response to when a learner's permit holder is allowed to drive without supervision is when they obtain a full driver's license. At this stage, they have completed the necessary requirements, including the required practice hours and passing the driving skills test, proving that they possess the necessary knowledge and skills to drive independently. Until a full license is obtained, learner's permit holders must always have an adult driver in the vehicle who is licensed and has significant driving experience to provide guidance and ensure safety on the road.

As for the other options, simply turning 18 does not grant the permit holder the right to drive without supervision, as age alone does not equate to the skills and knowledge required for independent driving. Similarly, holding the permit for a period of six months may be a requirement for practice but does not necessarily mean they can drive unsupervised; that is contingent on achieving a full driver's license. Therefore, it is critical to recognize that unsupervised driving is only permissible once they have met all legal requirements associated with obtaining a full driver's license.