A. FADH₂, NADH, H₂0

B. O₂, FADH₂, NADH

C. FADH₂, O₂, NADH

D. NADH, O₂, FADH₂

E. FADH₂, NADH, O₂

After the citric acid cycle, the majority of energy is stored in the reduced electron carriers NADH and FADH₂. Electrons from the carriers are donated to the electron transport chain in the mitochondrial inner membrane and are ultimately transferred to oxygen to produce water. The proton gradient that is produced during this process can generate ATP by passing through the inner mitochondrial membrane associated ATP synthetase.