This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nose and paranasal sinuses, Subject name: ENT
The prerequisite for endoscopic sinus surgery is 
Select and explain. 
A. MRI of paranasal sinuses, B. CT of paranasal sinuses, C. Mucocilliary clearing testing, D. Acoustic tests
B: CT of paranasal sinuses
Answer: B: CT of paranasal sinuses 
Explanation: Endoscopic surgery of inflammatory diseases of paranasal sinuses (sinusitis or polyp) requires a very detailed preoperative knowledge of the individual anatomical conditions and pathological changesCT scan is used best to visualize sinus areasCT scan provides an excellent definition of paranasal sinuses and is a prerequisite for endoscopic surgeryRef: PL Dhingra, Diseases of Ear, Nose & Throat, 7th edition, pg no. 220 - 221