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
If a permanent first molar is lost, the permanent second molar drifts to the: 
Select and explain. 
A. Buccal side, B. Distal side, C. Mesial side, D. Lingual side
C: Mesial side
Answer: C: Mesial side 
Explanation: None