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
[{'content': 'A protaper F2 series Gutta Percha when cut 1 mm in apical position of canal. The preparation as per in apical region is? \nSelect and explain. \nA. 0.29 mm, B. 0.30 mm, C. 0.31 mm, D. 0.33 mm', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]