Answer:y=1/2x
Explanation:
If it were to be y=2x, the blue line would be steeper than the black line, but it isn't, so that would be canceled out.
If it were to be y=0.001x, the blue line would be almost flat, which it isn't, so that is also canceled out.
If it were y=-x, the line would be heading down south instead of going up, so that would also be canceled out.
You are left with y=1/2x