In order to find the radius of this circle, we can compare this equation with the following standard equation of a circle:
[tex](x-h)^2+(y-k)^2=r^2[/tex]Comparing the right side of each equation, we have:
[tex]\begin{gathered} r^2=4 \\ r=\sqrt[]{4} \\ r=2 \end{gathered}[/tex]The radius is 2 units, therefore the correct option is the first one.
