In the context of Gibbs free energy, energy is released from ATP when which process occurs?

• A. ATP binds to an enzyme active site without bond cleavage, and the binding alone releases usable cellular energy as a strongly exergonic step.
• B. ADP is phosphorylated to ATP, which has a negative Gibbs free energy change ($\Delta G<0$).
• C. ATP is hydrolyzed to ADP and inorganic phosphate (Pi), resulting in a net decrease in Gibbs free energy ($\Delta G<0$).
• D. ATP is synthesized from AMP and pyrophosphate (PPi), releasing energy because entropy decreases.

Answer: (C)