What are the requirements for a supervising driver in New Jersey?

The correct choice outlines the specific requirements for a supervising driver in New Jersey, which are crucial for ensuring safety and compliance with state regulations. In New Jersey, a supervising driver must be at least 21 years old, ensuring that they have sufficient maturity and experience to guide a learner. Additionally, this individual must occupy the front seat of the vehicle, providing direct oversight. Another key requirement is that the supervising driver must hold a valid New Jersey driver's license for a minimum of three years, which ensures that they have ample driving experience and a good understanding of New Jersey's driving laws and routes.

The other options present incorrect age limits, seating positions, and licensing durations that do not align with the requirements set by the New Jersey Motor Vehicle Commission.