What is required for a learner's permit holder to drive legally?

Answer: B — To have a licensed driver aged 21 or older present

For a learner's permit holder to drive legally, it is required that they have a licensed driver who is 21 years old or older present in the vehicle. This requirement is in place to ensure that the learner is monitored by an experienced driver who can provide guidance and support during the learning phase. Having an adult driver with more experience can help ensure the safety of the learner and others on the road, especially since new drivers may not be fully accustomed to handling various driving situations. The other options, while related to the driving experience, do not meet the specific legal requirement for a learner's permit holder. Having a parent in the vehicle may provide additional support, but the law specifically mandates the presence of a licensed driver who is at least 21 years of age. Completing a certain number of driving hours is part of gaining progress towards a full license, but it is not a requirement for legal driving with a learner's permit. Finally, while passing the written exam is necessary to obtain the learner's permit, it does not influence the legality of driving itself without the presence of an appropriate supervising driver.