Which of the following is a requirement for qualified personnel?

Qualified personnel must have their duties aligned with the code because this ensures that they are adhering to the established safety standards, regulations, and operational procedures that govern the LP-Gas industry. This alignment is essential for maintaining safety, efficiency, and compliance with legal requirements. When personnel's responsibilities are in accordance with the code, it significantly reduces the risk of accidents or violations, ensuring a safe environment for all employees and customers.

Other criteria like working full-time, having graduate degrees, or being long-term employees are not universally required for someone to be considered qualified in this context. The focus on compliance with the code emphasizes the importance of regulatory adherence over the specific employment conditions or educational background of the personnel involved.