A tank is filled upto a height $h$ with a liquid and is placed on a platform of height $h$ from the ground. To get maximum range $x_{m}$, a small hole is punched at a distance of $y$ from the free surface of the liquid. Then
(a) $x_{m}=2 h$
(b) $x_{m}=1.5 h$
(c) $y=2 h$
(d) $y=0.75 h$