Answer:
3 to 5
Step-by-step explanation:
The pH scale is from 0 to 14.
Acids have a pH of anything less than 7.
Anything with a pH greater than 7 is considered to be a base.
If a solution has a pH of 7, it is neutral.
3 to 5 is in the range of less than 7, so a solution of an acid can have this pH.
6 to 8 includes less than 7 , 7 and greater than 7, so it is not just in the range of an acid.
9 to 11 and 12 to 14 are both in the range of greater than 7, so they have to be bases.
Therefore, the correct answer is 3 to 5.