What is one of the key steering system parts?

The key steering system part in this context is the tie rod. The tie rod serves as a critical component in the steering mechanism of a vehicle, connecting the steering gear to the wheel assembly. It helps in transmitting the steering input from the driver to the wheels, allowing for controlled movement and maneuverability of the vehicle.

The proper function of the tie rod is essential for safe driving, as it affects the alignment and stability of the vehicle. If the tie rod is worn or damaged, it can lead to steering issues, such as difficulty in steering or misalignment, which can compromise safety on the road.

The other choices, while important vehicle components, do not pertain to the steering system. The battery provides electrical power, the brake pedal is crucial for stopping the vehicle, and the transmission is responsible for transferring power from the engine to the wheels. However, none of these parts directly contribute to the steering function.