Which of these is a reason that could lead to license suspension?

Failure to carry insurance is a valid reason for license suspension because, in Idaho, as in many other states, maintaining proper vehicle insurance is a legal requirement. If a driver is found to be operating a vehicle without the necessary insurance coverage, it can lead to serious consequences, including the suspension of their driving privileges. This regulation is in place to ensure that all drivers have financial responsibility in case of an accident, protecting not only themselves but also other road users.

In contrast, passing an exam, using turn signals, and obeying traffic signs are all indicators of responsible driving behavior and compliance with traffic laws, which do not result in negative consequences like license suspension. Instead, they contribute to safer driving practices and help maintain a valid driving record.