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
In schizophrenia, characteristic feature is: 
Select and explain. 
A. Formal thought disorder, B. Delusion, C. Hallucination, D. Apathy
A: Formal thought disorder
Answer: A: Formal thought disorder 
Explanation: A i.e. Formal thought disorder