Which of the following solutions containing only hydroxyl ions will liberate hydrogen gas when reacted with Mg metals?

• A.1.0 x 10^-5 moldm^-3
• B.1.0 x 10^-13 moldm^-3
• C.1.0 x 10^-3 moldm^-3
• D.1.0 x 10^-2 moldm^-3