Answer:
D. Highest increase in the multiple R2.
Explanation:
Included variables in a multiple regression model are those variables which have the most effect on the model ; variables which have no effect on the performance of the model ar discarded. Model performance are based on the variables affect the multiple R² value of the model. The R² value is the coefficient of determination which gives the proportion of change in predicted value based on the regression line. Higher R² value means the variable has greater effect in the model performance. Therefore, variables which have the highest increase on the multiple R² value , are included.