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

Multiple Choice

Which of the following is not a required condition for the error variable $$\varepsilon$$ in the simple linear regression model?

A) The probability distribution of $$\varepsilon$$ is normal.
B) The mean of the probability distribution of $$\varepsilon$$ is zero.
C) The standard deviation $$\sigma _ { \varepsilon }$$ of $$\varepsilon$$ is a constant, no matter what the value of x.
D) The values of $$\varepsilon$$ are auto correlated.