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
Children	of	parents	with	which	of	the	following
blood group combinations have the highest risk of
erythroblastosis fetalis: 
Select and explain. 
A. Rh+ father and Rh+ mother, B. Rh+ father and Rh- mother, C. Rh- father and Rh+ mother, D. Rh- father and Rh- mother
B: Rh+ father and Rh- mother
Answer: B: Rh+ father and Rh- mother 
Explanation: None