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
Grooves, which are present in gum pads between the
canine and the 1st molars and relates the upper and
lower gum pads are called as 
Select and explain. 
A. Gingival groove, B. dental groove, C. Vestibular sulcus, D. lateral sulcus
D: lateral sulcus
Answer: D: lateral sulcus 
Explanation: None