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': 'If a body is left undisturbed, for how long does post mortem staining persists - \nSelect and explain. \nA. Few hours, B. Few days, C. Few month, D. Persists till merges with discolouration of putrefaction', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]