Answer:
The correct answer would be b. the electron transport chain.
Electron transport chain ETC) refers to the transport of high energy electrons through the series of electron carrier complexes. The complexes associated with ETC are embedded in the inner mitochondrial membrane.
Products such as NADH and FADH₂ released from processes such as glycolysis, pyruvate decarboxylation, and Krebs cycle are used as electron donors in ETC.
The energy of electrons are used to pump protons into the inter-membrane space which leads to the generation of chemical gradient across the membrane.
This gradient is used by the enzyme ATP synthase (embedded in the inner membrane) to phosphorylate ADP into ATP.
It leads to the generation of approximately 34 ATP.
