Why Must the Transfer of Electrons from Glucose to Oxygen

Multiple Choice

Why must the transfer of electrons from glucose to oxygen during aerobic respiration take place in a series of steps?

A) The energy of the protons can be used to make ATP.
B) The energy of the electrons can be used to make ATP.
C) The energy of the electrons can be used to make ADP.
D) It is chemically impossible to transfer electrons directly from glucose to oxygen.
E) The chemical intermediates donate some of their electrons in order to increase the electron pool.