Which of the following clues indicates potential impairment during the walk and turn test?

The walk and turn test is a standardized field sobriety test used to assess a person's physical coordination and balance, which can be indicators of impairment, typically from alcohol or drugs. Stepping off the line during this test is a significant clue that suggests a lack of coordination and control.

When a person is able to maintain their balance and walk in a straight line, they are demonstrating a level of physical control that is expected in sober individuals. Touching the heel to toe is part of the test’s instructions and indicates that the person is attempting to follow the directions properly. Holding the breath is not a recognized indicator of impairment in this context.

Therefore, stepping off the line demonstrates difficulty in maintaining balance and form, which are essential for performing the task correctly. This behavior is a clear sign of potential impairment, making this the correct choice in identifying a clue during the walk and turn test.