This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Hemolytic anemia, Subject name: Pediatrics
Ba's hydrops fetalis is lethal because: 
Select and explain. 
A. Hb Ba's cannot bind oxygen, B. The excess a-globin form insoluble precipitates, C. Hb Ba's cannot release oxygen to fetal tissues, D. Microcytic red cells become trapped in the placental
C: Hb Ba's cannot release oxygen to fetal tissues
Answer: C: Hb Ba's cannot release oxygen to fetal tissues 
Explanation: Hb Ba: Most severe form of Alpha thalassemia As Hb Ba's consists of 4-gamma chains - have very high oxygen affinity Thus, it cannot release oxygen to fetal tissues.