According to the DSM-5,one of the five major symptoms of major depressive disorder is

A) problems thinking,concentrating,and making decisions.
B) frequent or unexpected panic attacks.
C) high levels of energy.
D) ability to complete routine tasks involved in daily living easily.

Symptoms

Observable signs or indicators of a disease or condition experienced by an individual.

Major Depressive Disorder

A mental disorder characterized by a pervasive and persistent low mood accompanied by low self-esteem, and by a lack of interest or pleasure in normally enjoyable activities.

DSM-5

Stands for Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, which is a comprehensive classification and diagnostic guide used by mental health professionals.