Answer
The equation matches with the graph labeled as I.
Work Step by Step
$4x^2+y^2=4$
$\frac{4x^2}{4}+\frac{y^2}{4}=1$
$\frac{x^2}{1}+\frac{y^2}{4}=1$
$\frac{x^2}{1^2}+\frac{y^2}{2^2}=1$
$2\gt1$: major axis is vertical.
Equation when major axis is vertical:
$\frac{x^2}{b^2}+\frac{y^2}{a^2}=1$
So,
$a^2=2^2$
$a=2$
Vertices: $(0,±a)=(0,±2)$
The equation matches with the graph labeled as I.
