What is the volume of $0.1\: M \: H_2SO_4$ required in litres to neutralize completely 1 litre of a solution containing 20 g of $NaOH$ ?

Question

$\begin {array} {1 1} (1)\;5.0 & \quad (2)\;0.5 \\ (3)\;2.5 & \quad (4)\;10.0 \end {array}$