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
How does root caries appear in cross section? 
Select and explain. 
A. Rhomboidal, B. U shaped, C. V shaped, D. Inverted V shaped
B: U shaped
Answer: B: U shaped 
Explanation: Root caries: U shaped
Pit and fissure caries: Inverted V shaped
Smooth surface caries: triangular/ cone shaped