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: Pathology
Stain used to diagnose amyloidosis: September 2008 
Select and explain. 
A. Methylene blue, B. Acid fast stain, C. Rose bengal, D. Congo red
D: Congo red
Answer: D: Congo red 
Explanation: Ans. D: Congo red