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
Tapping is required in a screw which is: 
Select and explain. 
A. Fluted., B. Non fluted., C. Self drilling., D. Self tapping.
B: Non fluted.
Answer: B: Non fluted. 
Explanation: Self tapping screw eliminates the need for tapping. Fluted screws have flutes at the end that act as tap and collect bone debris as the screw is advanced.