A vehicle displaying a red triangle on its back cannot travel faster than:

A vehicle displaying a red triangle on its back indicates that it is a slow-moving vehicle, meant to alert other drivers about its reduced speed. In Wyoming, as in many other states, a slow-moving vehicle is not allowed to travel faster than 25 miles per hour. This regulation is important to ensure safety on the roads, as slow-moving vehicles, like farm equipment or certain types of construction vehicles, can pose hazards to faster-moving traffic if their speed is not clearly communicated.

Thus, the correct answer establishes the maximum speed limit for such vehicles, helping to prevent accidents and allowing other drivers to adjust their speed accordingly when they encounter them on the road. Keeping these regulations in mind reinforces safe driving practices in various circumstances.