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: Surgery
Best for staging anal Ca. Is 
Select and explain. 
A. MRI, B. PET CT, C. CECT, D. Transrectal usg + DRE
B: PET CT
Answer: B: PET CT 
Explanation: Overall best for staging is PET CT.
For T stage transrectal usg is used.