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': "Locard's exchange principle is for \nSelect and explain. \nA. Detecting poisoning, B. Estimating the age, C. Finding out time since death, D. Detecting crime", 'role': 'user'}, {'content': 'Answer: D \nExplanation: Locards principal of exchange states that whenever two bodies come in contact with each other, there is exchange of material between the two and so a criminal can be linked to crime.', 'role': 'assistant'}]