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
Walls of the CT scanner room are coated with – 
Select and explain. 
A. Lead, B. Glass, C. Tungsten, D. Iron
A: Lead
Answer: A: Lead 
Explanation: Lead is the most common agent used in modern constructions (Room design) to offer radiation shielding.