This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: miscellaneous, Subject name: Pathology
[{'content': 'Which of the following is a negative stain- \nSelect and explain. \nA. Negrosin, B. Fonatana, C. ZN stain, D. Albe stain', 'role': 'user'}, {'content': 'Answer: A \nExplanation: list of negative stains: Nigrosin (a black synthetic dye) or India ink (an aqueous suspension of carbon paicles) Phosphotungstic acid is a common negative stain for viruses, nerves, polysaccharides, and other biological tissue materials.', 'role': 'assistant'}]