Please elaborate how it's initial velocity doesn't alter their range?

Projectile Projected Horizontally -

$t=\sqrt{\frac{2h}{g}}$​​​

 Let Y is along vertical direction and x-axis is along x-axis, then

$S_y =u_{y}t +\frac{1}{2}{a}_y{t}^2$

$t=\sqrt{\frac{2h}{g}}$

Since h is same for both, both will reach simultaneously.

Option c is correct
Regards