Answer:
The correct option is: d. all of the above
Explanation:
Teeth whitening is the method or technique used to lighten the color of the discolored or the stained teeth.
There are various in-office and at home teeth whitening methods that can be used. The in-office methods include various light-accelerated bleaching, and at home teeth whitening methods includes various strips and gels, whitening toothpastes, whitening rinses, and tray based tooth whiteners.