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
Locard's exchange principle is for- 
Select and explain. 
A. Detecting poisoning, B. Estimating the age, C. Finding out time since death, D. Detecting crime
D: Detecting crime
Answer: D: Detecting crime 
Explanation: D i.e. Detecting crimes