Answer
The equation with the graph labeled as II.
Work Step by Step
Equation of a parabola with vertical axis (vertex at origin): $x^2=4py$
$x^2=-6y$
So:
$4p=-6$
$p=-\frac{3}{2}$
Parabola opens downwards. Also, when $y=-1$, then $x=±\sqrt 6\approx±2.45$
The equation with the graph labeled as II.
