the equation of the line

Answer: C (y=-2x-1)
Step-by-step explanation:
1) Find the slope:
I find two points (-1,1) and (1,-3). You can do y2-y1/x2-x1 or rise over run. In this case I used rise over run which gave me 2. Seeing that the graph is decreasing the slope is negative, leaving C as my option.