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: Gynaecology & Obstetrics
[{'content': 'Lifespan of the fetal RBC approximately is \nSelect and explain. \nA. 60 days, B. 100 days, C. 80 days, D. 120 days', 'role': 'user'}, {'content': 'Answer: C \nExplanation: The lifespan of fetal red cells is\xa080 days\xa0and Rh factor is developed by 38 days.', 'role': 'assistant'}]