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: Microbiology
[{'content': "One of the following staining method is an example of negative staining - \nSelect and explain. \nA. Graim's staining, B. Fontana's staining, C. India ink preparation, D. Ziehl-Neelsen staining", 'role': 'user'}, {'content': 'Answer: C \nExplanation: Why is it necessary to use stained preparations in microbiology?\n\nLive bacteria do not show much structural details under the light microscope due to lack of contrast.\nHence it is customary to use staining techniques to produce colour contrast.\n\n\nMethods are -', 'role': 'assistant'}]