What verbal sign may indicate that a driver is impaired?

Frequent repetition of questions can serve as a verbal sign that a driver is impaired because it suggests cognitive difficulties that are often associated with intoxication or drug influence. When a person is under the influence, they may struggle with memory retention and processing information, causing them to ask the same questions multiple times without recalling previous answers. This behavior could indicate that their cognitive functions are not operating normally, which is a key aspect law enforcement looks for during traffic stops.

The other options, while they may reflect aspects of communication, such as clear speech or engaging conversation, do not signal impairment. Clear and coherent speech suggests a level of cognitive clarity and control, while expressing gratitude towards the officer could be seen as reflective of social awareness and civility. These traits would typically indicate that the driver is functioning normally rather than being impaired.