Final answer:
If the error term is correlated with any of the independent variables, the OLS estimators are biased and inconsistent.
Step-by-step explanation:
If the error term is correlated with any of the independent variables, the OLS estimators are biased and inconsistent.
If there is a correlation between the error term and any independent variable, it implies that the error term is not independent of the independent variables. This violation of the classical assumptions of OLS regression results in biased and inconsistent estimates.
Therefore, the correct answer is (a) Biased and inconsistent.