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
Which of the following stains can be used to demonstrate fat? 
Select and explain. 
A. Oil red, B. Sudan black B, C. Osmium tetroxide, D. All of the above
D: All of the above
Answer: D: All of the above 
Explanation: Fat / Lipid can be demonstrated by oil red O, Sudan black B or sudan IV, Osmium tetroxide.