A number of example plots of residuals from regression analysis are shown below. 41 4D PDT 41 4: 4t] 42 4 43 43 . 4D 43 opy 04 404a 10 which one of the following statements is true? 0 In graph (a), the variation of the residuals increases systematically indicating a violation of the constant variance assumption of regression. O In graph (b), the residuals show a clear curved pattern, indicating a violation of the assumption that there is a linear relationship between the mean of Y and X. D In graph (C), most of the residuals are randomly scattered around zero but one observation yields a much larger residual indicating a potential outlier. D In graph (d), the residuals show no systematic pattern, indicating that assumptions of constant variance and a linear relationship between the mean of Y and X are satisfied