Which of the following behaviors is a potential sign of impairment?

The presence of unpredictability, defensiveness, and irritability can indeed signal potential impairment in an individual. These behaviors often indicate an inability to maintain control over emotions and reactions, which may be a result of substance use or other impairments. Unpredictability can lead to erratic performance, while defensiveness might suggest that an individual is struggling to cope with situations that would typically be handled with poise. Irritability is often a manifestation of stress or underlying issues, further indicating that a person may not be in a clear, productive state of mind.

In contrast, consistent performance and reliability, willingness to accept feedback, and enthusiastic participation in meetings are all behaviors that reflect positive engagement and stability in the workplace. Such traits typically demonstrate that an individual is functioning well and is not likely exhibiting signs of impairment. Therefore, the behaviors noted in the correct choice are more indicative of a need for intervention or support.