In the Multiple Regression Model, the Adjusted $R ^ { 2 } , \bar { R } ^ { 2 }$

Multiple Choice

In the multiple regression model, the adjusted $R ^ { 2 } , \bar { R } ^ { 2 }$

A) cannot be negative.
B) will never be greater than the regression $R ^ { 2 }$
C) equals the square of the correlation coefficient r .
D) cannot decrease when an additional explanatory variable is added.