Left line is defined when x < 1 (x is less than 1). The point is not full and that means that x = 1 is not included.
Right line is defined when x is greater or equal to one x ≥ 1.
Options that have x < 1 and x ≥ 1 are b and d, so the answer is one of those.
Equations of the lines are in slope-intercept form y = mx + b, where m is slope and b is y-intercept.
Right line has steeper slope than left line, so the slope of right line will have bigger absolute value. That is the case with option d. (Left line has slope -1 and right one has slope -2, absolute value of right slope is bigger.)
You could also check with y-intercepts. Left line has y-intercept at y = 2 and left line is defined when x < 1. Only option d meets these conditions.
