Give the hydronium ion and hydroxide ion concentrations of solutions with the following values of pH. pH 9.0:
a) 1 × 10⁻⁹ M, 1 × 10⁻⁵ M
b) 1 × 10⁻⁵ M, 1 × 10⁻⁹ M
c) 1 × 10⁻⁹ M, 1 × 10⁻⁹ M
d) 1 × 10⁻⁵ M, 1 × 10⁻⁵ M