This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General anatomy, Subject name: Anatomy
[{'content': 'Which of the following is a negative stain \nSelect and explain. \nA. Fontana, B. ZN stain, C. Nigrosin, D. Albe stain', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Negative stain is a technique in which background is stained leaving the actual specimen untouched.and this visible. In contrast with positive staining.the actual specimen is trained..nigeosin and indian ink are negative stains', 'role': 'assistant'}]