Final answer:
A 20 volume hydrogen peroxide solution will generally lift the hair 10 levels. Therefore, the correct option is A.
Step-by-step explanation:
The 20 volume hydrogen peroxide solution will generally lift the hair 10 levels.
Hydrogen peroxide is commonly used as a bleaching agent for hair. The concentration of the hydrogen peroxide solution determines its strength. The term 'volume' refers to the amount of oxygen gas released per volume of hydrogen peroxide during decomposition.
A 20 volume hydrogen peroxide solution is equivalent to a 6% hydrogen peroxide solution. It is strong enough to lighten the hair by about 10 levels. Higher volume solutions may lift the hair by more levels, but they can also be more damaging to the hair.