Answer
Vertices: $(2,\ 0)$ and $(-2,0)$.
Foci: $(\sqrt{5}, 0)$ and $(-\sqrt{5}, 0)$.
Matches graph (b).
Work Step by Step
The transverse axis lies on the x-axis.
$a^{2}=4$
$\mathrm{a}=2$
The vertices are $a$ units from the center
$(2,\ 0)$ and $(-2,0)$.
The foci are $c$ units from the center.
$b^{2}=1$
$c^{2}=a^{2}+b^{2}=4+1=5$
$c=\sqrt{5}$
Foci: $(\sqrt{5}, 0)$ and $(-\sqrt{5}, 0)$.
Matches graph (b).