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: Radiology
[{'content': 'Most radio resistant phase in cell cycle – a) G1b) Early Sc) Late Sd) G2 \nSelect and explain. \nA. c, B. bc, C. bd, D. ac', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]