This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Psychiatry, Subject name: Medicine
Delusion is 
Select and explain. 
A. Perception, B. Thought, C. Insight, D. Depression
B: Thought
Answer: B: Thought 
Explanation: (Thought) (60- 61- Neeraj Ahuja 6th)* Delusion is a disorder with disturbed content of thought* Hallucination & Illusion are disorders of perception* Delirium & dementia are disorders of cognition* Insight is disturbed in psychosisDELUSION - False belief based on in correct inference about external reality; not consistent with patient's intelligence and cultural back ground that cannot be corrected by reasoning