Answer:
b.

Step-by-step explanation:
is just some logic. we see the second unit on the x-axis is 4, so let's try that. -0.03 * 4 = -0.12. -0.12 + 18.4 = 18.28. 18.28 lines up with the 18.3 measurement we see. the next closest option brings us to 17.8, so we'll go with b.