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
Characteristics of benign tumor of lung in X-ray is: 
Select and explain. 
A. Size > 5 cm diameter, B. Cavitation, C. Peripheral location, D. Concentric dense calcification
D: Concentric dense calcification
Answer: D: Concentric dense calcification 
Explanation: Ans. Concentric dense calcification