This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Hemoglobinopathies: Sickle cell anemia, Subject name: Pathology
[{'content': 'In sickle cell crisis bone pain is due to:- \nSelect and explain. \nA. Bone infarction, B. Osteroporosis, C. Osteomalacia, D. Periosteal reaction', 'role': 'user'}, {'content': "Answer: A \nExplanation: - Abnormal shape of RBC - Occlusion of small vessels of bone - bone infarction - resulting in pain If bones of hand & feet are involved - Hand foot syndrome Long bones - Avascular necrosis of femur veebral column - 'H' shaped veebra/ cod fish veebra/ fish mouth veebra -X ray skull - crew cut appearance (Hair on end appearance)", 'role': 'assistant'}]