What should be checked regarding the bus's tires during a pre-trip inspection?

During a pre-trip inspection, checking the bus's tires primarily focuses on ensuring they are properly inflated and possess adequate tread depth. Proper inflation is crucial for tire performance, safety, fuel efficiency, and preventing blowouts. Adequate tread depth is essential for maintaining traction on various road surfaces, especially in adverse weather conditions, which helps ensure safe stopping distances and handling.

The other choices do not address critical aspects related to tire safety and performance. The model year and brand of the tires do not directly impact their functionality as long as they meet safety standards. Additionally, while visibility in some contexts might be relevant, painting tires is not a standard or necessary practice for ensuring their effectiveness or safety.