In multiple regression,what does the parameter ² measure?

A) The variability of the responses about the population regression equation
B) The degrees of freedom associated with s²
C) The subpopulation means
D) None of the above

The parameter σ² represents the residual standard error or the standard deviation of the error term. It measures the variability of the responses about the population regression equation. Therefore, option A is the correct answer. Option B is incorrect because it refers to the degrees of freedom associated with a different term. Option C is incorrect because it refers to the subpopulation means, which are not captured by this parameter. Option D is incorrect because A is the correct answer.