If the PH of a Solution Is Decreased from 9

If the pH of a solution is decreased from 9 to 8, it means that the

A) concentration of H⁺ has decreased to one-tenth (1/10) what it was at pH 9.
B) concentration of H⁺ has increased 10-fold (10X) compared to what it was at pH 9.
C) concentration of OH⁻ has increased 10-fold (10X) compared to what it was at pH 9.
D) concentration of OH⁻ has decreased to one-tenth (1/10) what it was at pH 9.
E) Both B and D are correct.