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
Ultrasonography transducer contain – 
Select and explain. 
A. Sodium fluoride, B. Lead Zirconate, C. Caesium fluoride, D. None
B: Lead Zirconate
Answer: B: Lead Zirconate 
Explanation: Lead zirconate titanate (PZT) is the most widely used material in the ultrasound transducers / probes replacing the firstly discovered barium titanate.