Answer:
b
Explanation:
In y=mx+b form, the b is the y-intercept, therefore where the line crosses the y-axis on the graph. In this graph, the line crosses the y-axis at 100. This means that the "b" value is 100. So far, our equation is y=mx+100.
Next, to find m, you go to any other point on the graph and see how much units (rise over run) you went to get there. I picked the point (2,150), You can see that it took me 1 unit up and 2 units to the right to get to that point, leading us to believe the slope is 1/2.
Finally, put everything together and you get the answer of y=1/2x+100 (the letters do not matter) :)