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: Dental
In an anterior tooth to be restored with composite restoration, which of the following regarding the primary resistance form is false? 
Select and explain. 
A. Horizontal pulpal and gingival walls, B. All unsupported enamel need not be removed, C. Rounding of internal line angles, D. None of the above
B: All unsupported enamel need not be removed
Answer: B: All unsupported enamel need not be removed 
Explanation: Weakened, friable tooth structure always should be removed at this step (Primary resistance form) in the preparation. Unsupported but not friable enamel may be left for esthetic reasons in anterior teeth, where stresses are minimal and a bonded composite restoration is anticipated.​
NOTE: Rounding of axiopulpal line angle, rounding of internal line angles and horizontal pulpal and gingival walls are primary resistance forms.
Reference: Sturdevant operative dentistry. 7th EDITION, Page No:128