When Evaluating the Output of a Multiple Regression Model, One

When evaluating the output of a multiple regression model, one needs to check

A) the validity of the entire model using the criteria of economic plausibility, goodness of fit, and significance of slope.
B) the validity of the entire model using the criteria of economic plausibility only since the goodness of fit and significance of slope validity have been addressed in the multiple regression runs of data.
C) the validity of the last data set run using the criteria of economic plausibility, goodness of fit, and significance of slope.
D) the validity of the model using the first and last set of data run using the criteria of economic plausibility, goodness of fit, and significance of slope.