What is the purpose of using a low gear while descending a steep hill?

Using a low gear while descending a steep hill is primarily important for maintaining better control and reducing brake wear. When a driver shifts to a lower gear, it allows the engine to help slow down the vehicle through engine braking. This reduces reliance on the brakes, which can overheat and wear out quickly if used excessively during a long descent.

In addition, a lower gear increases the vehicle's ability to handle steep slopes by enhancing traction and stability. As the vehicle moves downhill, the engine resistance in a low gear prevents it from accelerating uncontrollably, thus providing the driver with greater control over speed and direction. This is especially crucial in commercial driving, where maintaining safety and vehicle integrity is paramount.

The other options do not accurately reflect the benefits of using low gear. Increasing engine power and speed is not desirable when descending, as this could lead to loss of control. Engaging cruise control is not typically advisable on steep hills, as it may not respond appropriately to changes in gradient. Minimizing fuel consumption is not a primary concern when descending; the focus should be on safety and control.