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
Polka dot sign on CT is a feature of 
Select and explain. 
A. Vertebral hemangioma, B. Eosinophilic granuloma, C. Osteosarcoma, D. Ewing's sarcoma
A: Vertebral hemangioma
Answer: A: Vertebral hemangioma 
Explanation: Polka dot sign/ Corduroy/vertical striations – Vertebral hemangioma.