This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Psychiatry
[{'content': 'Dysthymia is - \nSelect and explain. \nA. Chronic mild depression, B. Chronic severe depression, C. Bipolar disorder, D. Personality disorder', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Mild depression with the chronic course (≥ 2 years) is called dysthymia.', 'role': 'assistant'}]