Consider the Following Plot of Residuals Versus X for a Regression

Multiple Choice

Consider the following plot of residuals versus x for a regression analysis. Based on the plot, what problem with the regression model or data is most noticeable?

A) The variances are not constant.
B) The mean of Y is not a linear function of X.
C) The variance of Y is not constant at each X.
D) There is an outlier in the data.