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
Mesial and distal wall of class V cavity depends on: 
Select and explain. 
A. Direction of enamel rods, B. Presence of carious lesion, C. Contour of gingiva, D. Location of contact area
A: Direction of enamel rods
Answer: A: Direction of enamel rods 
Explanation: None