A Reaction Is at Equilibrium at a Given Temperature and Constant

A reaction is at equilibrium at a given temperature and constant pressure when

A) ( $\Delta$ S _rxn = 0.)
B) ( $\Delta$ S $\degree$ rxn =0.)
C) ( $\Delta$ G_rxn = 0.)
D) ( $\Delta$ G $\degree$ _rxn = 0.)
E) ( $\Delta$ H_rxn = 0.)