Final answer:
The product that comes in powder form and when mixed with hydrogen peroxide becomes a strong lightening product is pre-lightener.
Step-by-step explanation:
The product that comes in powder form and when mixed with hydrogen peroxide becomes a strong lightening product is pre-lightener (option C).
Permanent hair coloring requires three components: a dye precursor, a coupling agent, and an oxidant. The pre-lightener is the oxidant in this process and when mixed with hydrogen peroxide, it oxidizes the dye precursor and lightens the hair.
For example, in the oxidation of p-phenylenediamine to the quinonediimine, the pre-lightener acts as the oxidant to produce larger dye molecules that become locked inside the hair.