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
The incisal edges and the incisal thirds of facial surfaces of mandibular incisors and canines generally oppose lingual surfaces of maxillary incisor and canines: 
Select and explain. 
A. Within the incisal thirds, B. At the junction of middle and cervical thirds, C. At the linguo cervical ridges, D. Immediately incisal to cingulam
A: Within the incisal thirds
Answer: A: Within the incisal thirds 
Explanation: None