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: Pediatrics
[{'content': "Ba's hydrops fetalis is lethal because - \nSelect and explain. \nA. 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", 'role': 'user'}, {'content': "Answer: C \nExplanation: Ans. is 'c' i.e., Hb Ba's cannot release oxygen to fetal tissues `In the foetus excess gamma globin chains form tetramers (Hb Bas) with such high affinity for oxygen that they deliver almost no oxygen to tissues' - Robbins o Clinically this condition manifests as hydrops fetalis and fetus shows features similar to those of erythroblastosis fetalis ----> Severe pallor, Generalized edema, Massive hepatosplenomegaly", 'role': 'assistant'}]