Answer:
B. Population regression line
Step-by-step explanation:
Error term refers to the sum of deviation within regression line which provides an explanation for the difference between the results of the model and actual observed results. It represents margin of error within a statistical model.
Error term is the distance from each point to the population regression line. It includes everything that differentiates your model from reality. Therefore, factors like nonlinearities, unpredictable effects, measurement errors, and omitted variables will be reflected.