Which of the following are the roles of the least square assumptions? (Check all that apply.) D A. if the least square assumptions hold, then X, will explain all of the variation of Y, in large samples. D B. The least square assumptions organize the circumstances that pose difculties for OLS regression. 1:] c_ The least square assumptions helpIestimate the values of the population parameters with certainty. D D. It the least square assumptions hold. then mathematically, the sampling distributions of OLS estimators are normal in large samples