So since the first point (0,30) has an x intercept of 0 and a y intercept of 30 We can immediately eliminate any that do not have an y intercept of 30 So choices a and b are automatically incorrect
and now to solve for slope we do (y2-y1)/(x2-x1) so we can choose any two points so I'll use points (0,30) and (1,33)
so 33-30=3 and 1-0=1
so we then do rise(y) over run (x) and we now know our unit rate is 3x