When is it permissible to use a handheld mobile device while driving according to Title 21?

The correct answer is that it is permissible to use a handheld mobile device while driving only in emergency situations. This principle aligns with the regulations stated in Title 21, which prioritize road safety and aim to minimize distractions for drivers. In emergency situations, such as when a driver needs to report a crime or medical emergency, using a handheld device becomes acceptable to respond to urgent circumstances. However, outside these situations, the law restricts the use of handheld devices to help prevent accidents caused by distracted driving.

Other options, such as using a device at any time or while stopped at traffic lights, do not align with the provisions intended to enhance safety on the roads. The use of a hands-free device might seem permissible under certain guidelines, but it does not include handheld devices, thus reinforcing why the restriction primarily favors emergency use only.