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': 'Gguardian of the genome"? \nSelect and explain. \nA. p53, B. Mdm2, C. pl4, D. ATM', 'role': 'user'}, {'content': 'Answer: A \nExplanation: . p53', 'role': 'assistant'}]