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
Rind sign is seen: 
Select and explain. 
A. Marfan syndrome., B. Osteopetrosis., C. Fibrous dysplasia., D. All of the above.
C: Fibrous dysplasia.
Answer: C: Fibrous dysplasia. 
Explanation: Radiologically the radiolucent lesions in fibrous dysplasia are surrounded by a thick sclerotic border and this is known as rind sign.