As square box of water has a small hole located in one of the bottom corner. When the box is full and sitting on level surface complete opening of the hole results in a flow of water with speed $v_0.$ When box is half empty, it is lilted by $45^{\circ}$. So that the hole is at lowest position. Now the water will flow with speed of

Question

$$\begin {array} {1 1} (a)\;v_0 \\ (b)\;\frac{v_0}{2} \\ (c)\;\frac{v_0}{\sqrt 2}\\ (d)\;\frac{v_0}{4 \sqrt 2} \end {array}$$