This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Thanatology, Subject name: Forensic Medicine
[{'content': 'Putrefaction sign first appears at \nSelect and explain. \nA. Liver undersurface, B. In mediastinum, C. Below the spleen, D. In kidney', 'role': 'user'}, {'content': 'Answer: A \nExplanation: First external sign of putrefaction is the greenish discolouration in right iliac fossa. Internally, first site of reddish brown discolouration is aoic intima and then the undersurface of liver', 'role': 'assistant'}]