What is the purpose of using a trailer brake control?

The purpose of using a trailer brake control is to provide the ability to manage the braking system of the trailer independently from the truck. This feature is crucial for maintaining vehicle stability and control, especially when hauling heavy loads. By adjusting the trailer brakes separately, the driver can fine-tune braking pressure to respond to specific driving conditions, thus preventing skidding or swaying that might occur if the truck and trailer were to brake simultaneously without coordination. The independent control helps in reducing stopping distances and allows for safer maneuvering, especially in slippery or steep environments.

The other options do not relate directly to the primary function of a trailer brake control. Enhancing fuel efficiency is influenced by various factors but not directly by the trailer brake system. Synchronizing the trailer's lights with the truck is managed through the electrical system and is unrelated to brake control. Distributing weight evenly on the trailer pertains more to load management than brake operation. Thus, the option regarding the independent control of the trailer's brakes effectively captures the essential role of the trailer brake control system.