Final answer:
In the context of hair coloring, using a toner on overlightened hair can lead to the hair being darker than desired, but when used properly, it can also correct brassy tones.
So The correct answer is Option A
Step-by-step explanation:
If the hair is overlightened, a toner may make the hair appear darker than desired. This is because toners are used to add pigment back into the hair that has been lightened too much, and sometimes this can result in a darker shade if the toner is overly pigmented or left on the hair for too long. However, if chosen correctly, a toner can help to correct the color by neutralizing unwanted brassy or yellow tones, making the hair look more natural or achieving the desired ashy or cool tone.
The correct answer is Option A