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
ABO incompatibility in Rh immunization has 
Select and explain. 
A. Protective effect, B. Harmful effect, C. No effect, D. None
A: Protective effect
Answer: A: Protective effect 
Explanation: 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.