Final answer:
Mixing Processing Solution with SEQ Color Gloss does not lighten natural pigmented hair, so the answer is A. 0 levels. Shades EQ is a demi-permanent color that tones and changes hair tone without lifting.
Step-by-step explanation:
When Processing Solution is mixed with SEQ Color Gloss, its action is not to lighten natural pigmented hair. Instead, this combination is meant to tone, refresh, deepen, or change the tone of the hair but does not lighten it. Therefore, the correct answer to how many levels the natural pigmented hair is lightened would be A. 0 levels. Shades EQ is a demi-permanent hair color, which is less strong than permanent hair color and does not lift the hair's natural pigment.