Answer
The equation matches with the graph labeled as II.
Work Step by Step
$16\gt4$: major axis is horizontal.
Equation when major axis is horizontal:
$\frac{x^2}{a^2}+\frac{y^2}{b^2}=1$
So,
$a^2=16$
$a=4$
Vertices: $(±a,0)=(±4,0)$
The equation matches with the graph labeled as II.