Final answer:
The given reaction, ATP -> ADP + P, is classified as an oxidation reaction.
Step-by-step explanation:
The given reaction, ATP -> ADP + P, is an example of an oxidation-reduction reaction because it involves the transfer of electrons.
In this reaction, ATP is oxidized to form ADP and an inorganic phosphate molecule (P), and during oxidation, electrons are transferred. Option C, oxidation reaction, is the correct classification for this reaction.