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: Medicine
[{'content': 'Children\tof\tparents\twith\twhich\tof\tthe\tfollowing\nblood group combinations have the highest risk of\nerythroblastosis fetalis: \nSelect and explain. \nA. Rh+ father and Rh+ mother, B. Rh+ father and Rh- mother, C. Rh- father and Rh+ mother, D. Rh- father and Rh- mother', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]