Which One of the Following Phrases Correctly Completes the Sentence $\Delta$

Which one of the following phrases correctly completes the sentence "Chemical reactions occur spontaneously…"

A) …if $\Delta$ H for the reaction is < 0.
B) …if $\Delta$ S for the reaction is < 0.
C) …if the Gibbs free energy change for the reaction is positive.
D) …if the Gibbs free energy for the reaction is negative.
E) None of the phrases given