What additional requirement is there for a Class 1 licence besides the minimum age?

Answer: B — Must not be a novice driver

A Class 1 licence is required to operate heavy commercial vehicles, so the only additional requirement would be that the applicant must not be a novice driver. Options A and D are incorrect because having a high school diploma or holding a Class 5 licence does not guarantee that an individual has sufficient experience or skill to operate heavy commercial vehicles. Option C is incorrect because having a perfect driving record does not necessarily indicate experience in driving commercial vehicles.