With x=8, it means the line is vertical (up and down), it also means it is undefined.
In order to find the parallel line, it has to have the same slope. Different b value (mx+b, but the m has to be the same).
Since the question is asking for a parallel line, you know that it also has to be vertical, to keep it consistent.
Since it is asking for the line that passes through (-3, -2), you are looking at the x value which is -3, therefore x=-3
