Final answer:
Both Tech A and Tech B are correct, but they refer to different types of vehicles. Heavy trucks use air-operated brakes on the truck and hydraulic brakes on the trailer, while most conventional passenger vehicles use scrub brakes.
Step-by-step explanation:
Both Tech A and Tech B are correct, but they are referring to different types of vehicles.
Heavy trucks often use air-operated brakes on the truck and hydraulic brakes on the trailer. This is because the trailers have a different braking system than the truck itself. The air-operated brakes on the truck allow for more control and braking power, while the hydraulic brakes on the trailer are simpler and more cost-effective.
On the other hand, most conventional passenger vehicles use scrub brakes. Scrub brakes are a type of hydraulic brake system that use friction to slow down or stop the vehicle.