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 appliance used for uprighting of molar is 
Select and explain. 
A. Inclined plane, B. Removable appliance with long labial bow, C. Fixed appliance with auxiliary spring, D. Separating spring
C: Fixed appliance with auxiliary spring
Answer: C: Fixed appliance with auxiliary spring 
Explanation: A partial fixed appliance to upright tipped molars consists of bonded brackets on the premolars and canine in that quadrant and either a bonded rectangular tube on the molar or a molar band.
If the molar is severely tipped, a continuous wire that uprights the molar will have side effects (which almost always are undesirable) on the position and inclination of the second premolar. For that reason it is better to carry out the bulk of the uprighting by using an auxiliary uprighting spring.