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': 'First change in a dead body is: \nSelect and explain. \nA. Mummification, B. Greenish discolouration of RIF, C. Putrefaction, D. Maggot formation', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Greenish discolouration of RIF', 'role': 'assistant'}]