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': 'Dark ground microscopy is used to see - \nSelect and explain. \nA. Refractile organisms, B. Flagella, C. Capsule, D. Fimbriae', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Dark ground/ Darkfield microscope \n\nVery slender organisms such as spirochetes and filamentous organisms such as flagella are not visible under ordinary illumination.\n\n\n\nThe contrast in dark field microscopy gives an illusion of increased resolution so that these structures can be seen under the dark field microscope.\n\n\nIn darkfield microscopy, reflected light is used instead of the transmitted light used in the ordinary microscope.\n\n\nDark ground (dark field) microscopy is used for\n\n- Flagella\n- Spirochetes', 'role': 'assistant'}]