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
All of these are true for home bleaching technique, except: 
Select and explain. 
A. Dentist prescribed home technique, B. It contains 10-15% carbamide peroxide, C. Bleaching both arches at one time is preferred, D. Patient compliance is needed
C: Bleaching both arches at one time is preferred
Answer: C: Bleaching both arches at one time is preferred 
Explanation: HOME BLEACHING TECHNIQUE/NIGHT GUARD BLEACHING
Commonly used solution for night guard bleaching 

10% carbamide peroxide with or without carbopol. 
15% carbamide peroxide.
Hydrogen peroxide (1-10%). 

Key concept: 
Bleaching would be done only one arch at a time.