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: Pathology
[{'content': 'Conversion of normal cell into their tombstones is the hallmark of: \nSelect and explain. \nA. Coagulative necrosis., B. Liquefaction necrosis., C. Caseous necrosis., D. Gangrenous necrosis.', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]