Answer
Horizontal lines: C, D
Vertical lines: A, E
Neither: B
Work Step by Step
Horizontal lines have the form:
$y=c$ (where $c$ is a constant)
Vertical lines have the form:
$x=c$ (where $c$ is a constant)
We try to convert each equation to a horizontal or vertical line:
A. $x-6=0\rightarrow x=6$ (vertical line)
B. $x+y=0\rightarrow y=-x$ (diagonal line with slope -1)
C. $y+3=0\rightarrow y=-3$ (horizontal line)
D. $y=-10$ (horizontal line)
E. $x+1=5\rightarrow x=4$ (vertical line)
