What is the primary benefit of using mirrors while driving a commercial vehicle?

The primary benefit of using mirrors while driving a commercial vehicle is to increase visibility and minimize blind spots. Commercial vehicles, due to their size and dimensions, often have significant blind spots that can obscure the driver's view of nearby vehicles, pedestrians, and obstacles. Proper use of mirrors allows drivers to monitor their surroundings, making it easier to perform maneuvers such as lane changes, turns, and reversing safely. This increased visibility is vital for preventing accidents and ensuring the safety of both the driver and others on the road.

While other choices, like adjusting seating position or tracking vehicle mileage, may be aspects of operating a vehicle, they do not relate to the critical function of mirrors in maintaining awareness of the driving environment. Looking stylish while driving is also irrelevant to the primary purpose of mirrors. Thus, the correct answer emphasizes safety and efficiency in driving a commercial vehicle.