Answer
Choice B
Work Step by Step
A direct variation model takes the form $y=kx.$ The equation of Choice B, $2x-y=5,$ is equivalent to
\begin{align*}
2x-y-2x&=-2x+5
\\
-y&=-2x+5
\\
-1(-y)&=(-2x+5)(-1)
\\
y&=2x-5
.\end{align*}
Since the equivalent equation above takes the form $y=kx+c$ (and not $y=kx$), then it is not a direct variation equation. Hence, Choice B does NOT represent a direct variation.