Which of the Following Is Not a Required Condition for the Error

Which of the following is not a required condition for the error variable $\varepsilon$ in the simple linear regression model? $\begin{array}{|l|l|}\hline\text { A. } & \text {The probability distribution of \( \varepsilon \) is normal. }\\\hline \text { B. } & \text {The mean of the probability distribution of \( \varepsilon \) is zero. } \\\hline \text { C. } &\text {The standard deviation \( \sigma_{\varepsilon} \) of \( \varepsilon \) is a constant, no matter what the value of \( x \). }\\\hline \text { D. } &\text {The values of \( \varepsilon \) are auto correlated. }\\\hline\end{array}$