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: Forensic Medicine
[{'content': 'For diatoms test, the best site for taking a sample is - \nSelect and explain. \nA. Lungs, B. Bone marrow in Ulna, C. Bone marrow in femur, D. Muscle', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Diatoms can be demonstrated in all the given options.\n\n"The current technique for isolation of diatoms involve acid digestion of tissue-commonly bone marrow, lung,\xa0blood or kidneys with subsequent centrifugation and washing." - Parikh\n"Bone marrow of long bone (e.g. femur) is examined for diatoms. Kidney, lung, liver or brain is also washed and\xa01 x1 cm, pieces from the deeper tissue." - Reddy\n\nBut, the examiner is specifically asking for ideal tissue, which is bone marrow of long bones:\n\n\xad"The bone marrow is highly suitable and reliable. The bone marrow of long bones, such as femur, tibia, and\xa0humerus or sternum is examined for\xa0diatoms" - Reddy', 'role': 'assistant'}]