Question

Which of the following lines is parallel to x = 8?

Answer 1

Interestingly enough, the line x=8 is parallel to the y axis.  The line x=8 means that x=8 no matter what y equals.  
So any line that is parallel to the y axis could be the answer.

x=4
x=12
x=-17
x=-2.5   are all examples of lines that are parallel to x=8.  Perhaps that will answer your question.