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
Mesiolingual developmental groove is seen in 
Select and explain. 
A. Maxillary 1st premolar, B. Mandibular lateral incisor, C. Maxillary lateral incisor, D. Mandibular 1st premolar
D: Mandibular 1st premolar
Answer: D: Mandibular 1st premolar 
Explanation: Mesial Aspect

 Lingual cusp is around two third the size of the buccal cusp
 Extreme lingual slope is seen at the mesial marginal ridge
 Between the mesial marginal ridge and the mesiolingual cusp ridge is the mesiolingual developmental groove
 Mesial contact area is in the middle third