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
[{'content': 'Lipids do not stain with: \nSelect and explain. \nA. Oil red O, B. Congo red, C. Sudan III, D. Sudan black', 'role': 'user'}, {'content': 'Answer: B \nExplanation: . Congo red', 'role': 'assistant'}]