Final answer:
A dual air brake system features two separate air brake systems that work in tandem, each with its own air tanks and hoses, controlled by a single set of controls used by the driver. The correct answer to the question is option A.
Step-by-step explanation:
A dual air brake system is a critical component in many large commercial vehicles, particularly those that require a reliable and robust braking system, such as trucks and buses. This type of brake system is defined by having two separate air brake systems that work in conjunction to ensure safety and redundancy.
Each system has its own air tanks, hoses, and controls, yet they are connected to one set of brake controls used by the driver to operate the brakes.
Now, to address the question at hand, a dual air brake system A) has two air brake systems and one set of controls. This configuration allows the vehicle to maintain braking capability in case one system fails, providing an essential safety feature. The two systems are usually referred to as the primary and secondary systems.
The primary system typically operates the regular brakes on the rear axle(s), while the secondary system operates on the front axle and, sometimes, also supplements the rear brakes.
It's important to note that having a dual system doesn't necessarily mean that air pressure is built up more quickly (option B) since the air compressors must fill more volume. Additionally, having one set of air tanks and hoses (option C) is not characteristic of a dual system because each system has its own set of tanks and hoses to maintain separation and redundancy.
Lastly, it is a standard safety requirement to have warning alarms for low air pressure, but the number of alarms can vary and is not determined by the fact that the brake system is dual (option D).
The correct option is A, meaning a dual air brake system has two separate air brake systems that are controlled by one set of controls accessible to the driver.