This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Histo Pathology, Subject name: Pathology
[{'content': 'Which of the following is a negative stain: \nSelect and explain. \nA. Negrosin, B. Fonatana, C. ZN stain, D. Albert stain', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. (a) Negrosin(Ref: Bancroft's histological techniques, 7th edition)Examples of negative stain are:*Negrosin: Stains bacteria, Cryptococcus, test for viability (sperms)*India Ink: Stains Cryptococcus", 'role': 'assistant'}]