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': 'Shadow casting is done in \nSelect and explain. \nA. Light microscopy, B. Electron microscopy, C. Dark field microscopy, D. Atomic force microscopy', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Shadow casting - specimen is coated with a thin film of platinum or other heavy metals to increase the contrast of Electron microscope.', 'role': 'assistant'}]