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': 'ABO incompatibility in Rh immunization has \nSelect and explain. \nA. Protective effect, B. Harmful effect, C. No effect, D. None', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Answer- A. Protective effectABO incompatibility has protective effect against the development of Rh sensitization. This protective effect is signifcant when mother is type O and the father is A, B or AB.', 'role': 'assistant'}]