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 used for generating X-rays: 
Select and explain. 
A. Tungsten, B. Cobalt, C. Cadmium, D. Palladium
A: Tungsten
Answer: A: Tungsten 
Explanation: Ans. Tungsten