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
Isotope selectively concentrated in abscess cavities: 
Select and explain. 
A. Gallium, B. Technetium, C. Selenium, D. Chromium
A: Gallium
Answer: A: Gallium 
Explanation: Ans. Gallium