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': 'During which phase of the cell cycle the cellular content of DNA is doubled - \nSelect and explain. \nA. Mitotic phase, B. G1 phase, C. G2 phase, D. S phase', 'role': 'user'}, {'content': 'Answer: D \nExplanation: There are two resting phases and two active phases in the cycle.\nResting phases → G1\xa0& G2\nActive phases\n\n\nS-phase (synthetic phase)\xa0- As the name suggests, synthesis of new DNA takes place, i.e. doubling of DNA occurs.\nM-phase (mitotic phase)\xa0- Mitosis takes place and the daughter cells receive one copy of DNA. In this phase, cell number is doubled.', 'role': 'assistant'}]