Which type of oxygen system incorporates a rebreather bag-type mask?

The correct answer is the continuous flow system because this type of oxygen system is designed to provide a consistent and steady flow of oxygen to the user. In a continuous flow system, a rebreather bag-type mask collects exhaled air, allowing the wearer to breathe in a mixture of oxygen from the tank and re-inhale the oxygen they exhaled. This setup is especially beneficial as it helps in conserving oxygen while maintaining a steady supply.

The design of the continuous flow system is such that it maintains a constant oxygen concentration, which is vital for preserving the integrity of the cabin atmosphere and ensuring that the user receives adequate oxygen to meet their physiological needs, especially at high altitudes where oxygen levels are lower.