In the context of Gibbs free energy, how does ATP become ADP during a typical cellular energy-yielding reaction?

• A. ATP becomes ADP primarily by oxidation of its adenine base, producing ADP and $O_2$ as a byproduct.
• B. ATP becomes ADP by breaking the glycosidic bond between adenine and ribose, yielding free ribose and adenine.
• C. ATP is hydrolyzed by water to form ADP and inorganic phosphate, releasing free energy: $ATP+H_{2}O\to ADP+Pi+H+$
• D. ATP is phosphorylated to ADP by adding an inorganic phosphate group, which increases the free energy of the products.

Answer: (C)