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
"Target material" which produces X-rays in a diagnostic X-rays tube is made of: 
Select and explain. 
A. Lead, B. Tungsten, C. Cobalt, D. Copper
B: Tungsten
Answer: B: Tungsten 
Explanation: Ans. Tungsten