Answer :
Solution a contains more H⁺ cause:
[tex]C_{m}=\frac{n}{V}\\\\\\ C_{m} \sim n[/tex]
1×10⁻⁶ [H⁺] > 1×10⁻⁸ [H⁺]
[tex]C_{m}=\frac{n}{V}\\\\\\ C_{m} \sim n[/tex]
1×10⁻⁶ [H⁺] > 1×10⁻⁸ [H⁺]