The GLS Estimator

Multiple Choice

The GLS estimator

A) is always the more efficient estimator when compared to OLS.
B) is the OLS estimator of the coefficients in a transformed model, where the errors of the transformed model satisfy the Gauss-Markov conditions.
C) cannot handle binary variables, since some of the transformations require division by one of the regressors.
D) produces identical estimates for the coefficients, but different standard errors.