Which of the following is a symptom of a mental disorder?

Impaired behavior and function is a recognized symptom of a mental disorder. When someone is experiencing a mental health issue, it can significantly impact their ability to perform daily activities, maintain relationships, and function effectively in various settings, such as work and social environments. This impairment often manifests in various ways, including difficulty concentrating, erratic behavior, social withdrawal, or an inability to manage emotions appropriately.

In contrast, the other options refer to positive attributes that indicate good mental health. The ability to cope well with stress, strong emotional regulation, and high resilience to challenges reflect situations where an individual can manage life's difficulties effectively, demonstrating psychological health rather than a mental disorder. Therefore, recognizing impaired behavior and function as a symptom is crucial in identifying mental health issues and facilitating appropriate interventions or treatment plans.