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
Which of the following is Cemento-dentinal junction? 
Select and explain. 
A. Most important	anatomical	landmark	for determining the location of pulp chambers and root canal orifices, B. Point where pulp tissue ends and periodontal tissue begins, C. Space between major and minor foramina, D. Rounded edge that differentiates the termination of the cemental canal from the exterior surface of root.
B: Point where pulp tissue ends and periodontal tissue begins
Answer: B: Point where pulp tissue ends and periodontal tissue begins 
Explanation: None