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
Terminal portion of Hertwig's epithelial root sheath will form a tapering tooth root.The terminal portion has been called: 
Select and explain. 
A. Apical loop., B. Epithelial Diaphragm., C. Cementum., D. None of the Above.
A: Apical loop.
Answer: A: Apical loop. 
Explanation: The terminal portion of Hertwig's epithelial root sheath will form a tapering tooth root. The terminal portion has been called the apical loop.