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
Poor prognostic factor in schizophrenia is 
Select and explain. 
A. Acute onset, B. Middle age, C. Family history of affective disorder, D. Gradual onset
D: Gradual onset
Answer: D: Gradual onset 
Explanation: Gradual onset