Which one of the following is a validity condition for theory-based tests for regression?
A. The variability of the points around the regression line should not diff er as you slide along the x-axis.
B. There should be at least 10 successes and 10 failures in the data.
C. The variability of the explanatory variable should be the same as the variability of the response variable.
D. The scatterplot should show a positive association between the explanatory and response variables.