The choices are in the slope-intecept form: y = mx + b, where m is the slope and b is the y-intercept. Looking at the graph, the y-intercept is the point at which it intersects the y-axis. That would be -1. So, the answer is either the 1st or 2nd choice. Next, we find the slope. Take 2 points that lie along the line. For example, points (1,2) and (2,5). Calculate for the slope.
m = (y2-y1)/(x2-x1)
m = (5-2)/(2-1)
m = 3
Hence, the graph is y = 3x - 1