:6. Consider diagram ? on page ? of the test. It shows a scatter diagram, its approximate regression line, and four vertical line segments marked A,B,C, and D. Each of these line segments represents an error (where by the "error" of a point is meant its distance from the regression line). One of these errors is about the size of the rms error of th regression line. Which one?

a. A

b. B

c. C

d. D