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: Radiology
All are radiological features of sickle cell anemia except – a) Vertebra planab) Floating teethc) Bone infarctd) Marrow hyperplasiae) Secondary osteomyelitis 
Select and explain. 
A. ac, B. a, C. ab, D. bc
C: ab
Answer: C: ab 
Explanation: Bone infarct, marrow hyperplasia and secondary osteomyelitis occur in sickle cell anemia.