Which of the following actions is considered illegal while driving?

Driving with an expired license is considered illegal because it indicates that the driver is operating a vehicle without valid authorization. Each state requires drivers to maintain a valid driver's license, which includes renewing it regularly and adhering to any legal stipulations that accompany it. An expired license means the driver has not met these requirements and therefore does not have the legal right to operate a vehicle on public roads. It also poses a risk to public safety, as it may indicate that the driver has not complied with necessary testing or has any unresolved legal issues.

Using a turn signal, adjusting mirrors, and keeping hands on the wheel are all responsible actions while driving, and they contribute to safety and compliance with traffic laws.