This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Fundamentals in Radiology, Subject name: Radiology
Ultrasonography transducer contains - 
Select and explain. 
A. Sodium Fluoride, B. Lead Zirconate, C. Caesium Fluoride, D. Barium titanate
B: Lead Zirconate
Answer: B: Lead Zirconate 
Explanation: Lead Zirconate titanate is the most widely used piezoelectric material in the ultrasound transducers. Barium titanate was the first discovered piezoeletric material.