Suppose that your findings were as follows for the relationship between support for social welfare and income. Among whites, the significance level is .000 and Kendall’s tau = .40. Among African Americans, the significance level is .073 and Kendall’s tau = .034. Which of the following best describes the effects of the control variable?

A. The control variable has no effect.
B. The control variable has a small effect, but the effect is not big enough to make any difference.
C. The control variable has a substantial effect.
D. Based just on this information, we cannot really determine whether the control variable has an effect on the relationship between the dependent variable and the independent variable.

C.