This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Radiology
Gamma camera is used for 
Select and explain. 
A. Organ imaging, B. Measuring radioactivity, C. Monitoring surface contamination, D. RIA
B: Measuring radioactivity
Answer: B: Measuring radioactivity 
Explanation: (Ref: Grainger&;s diagnostic radiology, 6th ed; page 120)