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: Pathology
Which one of the following is a metric dental feature? 
Select and explain. 
A. Shovelling, B. Caravelli's trait, C. Mandibular molar groove pattern, D. Root length of maxillary canine
D: Root length of maxillary canine
Answer: D: Root length of maxillary canine 
Explanation: None