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
According to the percepts of vertical condensation technology, the apical foramen should be 
Select and explain. 
A. as large as practicable., B. as small as practicable., C. oval., D. circular.
B: as small as practicable.
Answer: B: as small as practicable. 
Explanation: None