Answer is:
A. spontaneous reactions release.
ATP
is short for adenosine triphosphate
Adenosine triphosphate converts to either
the adenosine diphosphate (ADP) or adenosine monophosphate
(AMP), in this process energy is released (for example glycolysis, the citric acid cycle or oxidative phosphorylation and beta-oxidation).
ATP is made of three components: the
triphosphate, the sugar ribose and a nitrogenous base (adenine).
