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': 'Sickle Cell anaemia all are true except \nSelect and explain. \nA. The shift from HbF to HbS occurs due to point mutation., B. Microvascular occlusion is a severe complication of SCA, C. Deoxygenation of RBC can lead to extensive membrane damage, D. Adults but not children; with  sickle  cell  disease  are  functionally  asplenic,  making them  susceptible  to  infections  caused  by  encapsulated  bacteria,  such  as  pneumococci.', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]