Answer:
The right answer is "a = 1, b = 0, c = 9"
Step-by-step explanation:
As the direction would have to be vertical, this same direction should therefore seem to have a consistent or constant x-coordinate.
∴ The equation a line is:
⇒  [tex]x=9[/tex]
On comparing it with:
⇒  [tex]Ax+By=C[/tex]
We get,
[tex]A=1\\[/tex]
[tex]B=0[/tex]
[tex]C=9[/tex]