For a Specific Chemical Reaction, the Value of DG ^$\circ$ Calculated from Tabulated Values of the Standard Gibbs Free

For a specific chemical reaction, the value of DG ^$\circ$ calculated from tabulated values of the standard Gibbs free energy of formation, DG ^$\circ$ _f, of the reactants and products is valid at

A) all temperatures
B) standard temperature and pressure (STP)
C) 0 K
D) 273 K
E) the temperature specified for the tabulated values