Answer
Graph E
Work Step by Step
Using $y=mx+b$ or the slope-intercept form of linear equations where $b$ is the $y-$intercept and $m$ is the slope, the given equation, $
y=-3
,$ has the following characteristics:
\begin{array}{l}\require{cancel}
\text{$y-$intercept: }
3
\\\text{slope: }
0
.\end{array}
The $y-$intercept is at the negative $y-$ axis. Since the slope is $0$, then the line is horizontal. These characteristics are best exemplified by $\text{
Graph E
.}$