Which of the Following Statements Describes the Phosphorylation Event That

Which of the following statements describes the phosphorylation event that occurs during the process known as "oxidative phosphorylation"?

A) A phosphate group is added to ADP.
B) ATP is hydrolyzed in order to add phosphate groups to protein substrates.
C) A phosphate group is added to molecular oxygen.
D) Inorganic phosphate is transported into the mitochondrial matrix, increasing the local phosphate concentration.