The pH of a 0.0001 M NaOH solution is (note: For strong bases such as NaOH, the hydroxide ion concentration is the same as the concentration of the base)
10
5
а
Ob
о с
Od
3
8

pH = 10

Explanation:

As the problem states, with strong bases the hydroxide ion concentration [OH⁻] is equal to the concentration of the base. That means that in this case:

With [OH⁻] we can calculate the pOH of the solution:

Then with the pOH, we calculate the pH of the solution:

the right answer is c i just did the question.