Which condition may indicate a faulty battery in a vehicle?

A faulty battery can lead to electrical system malfunctions within a vehicle, which is why this option is considered correct. The battery plays a critical role in storing and supplying the electrical energy required to operate various components of the vehicle—such as lights, the ignition system, and electronic control units. When the battery is weak or faulty, it may not provide enough voltage or current, leading to issues like dimming lights, failure to start, or erratic behavior of electrical accessories.

While increased fuel consumption, unusual tire wear, and frequent overheating can be symptoms of other issues in the vehicle—such as alignment problems, engine performance issues, or cooling system failures—they do not directly relate to the battery's state or functionality. Thus, electrical system malfunctions are the most indicative of a battery problem.