ANSWER
B. -1/2
EXPLANATION
The slope of a line from a graph can be found by dividing the rise by the run:
In this line the rise is 1 and the run is 2, but to the left, so it's negative. The slope of this line is:
[tex]\text{slope}=\frac{\text{rise}}{\text{run}}=\frac{1}{-2}=-\frac{1}{2}[/tex]
But we want to know the slope of a parallel line to the given line. It is the same slope, because paralell lines have the same slope.
