Answer:
c. diminished ability to think/concentrate, unusual motor behavior (i.e. catatonia)
Step-by-step explanation:
This is not a symptom of depression among the nine prominent symptoms since thinking process or concentration is normal or high in depression since the human mind is too preoccupied. A person suffering from depression does not commit unusual motor behavior such as catatonia since this is the symptom normally found in persons suffering from schizophrenia.