Final answer:
Electrons from the citric acid cycle are transported to the electron transport chain in the inner membrane of the mitochondria, where their energy is used to produce ATP.
Step-by-step explanation:
Electrons released during the citric acid cycle are transported to the electron transport chain (ETC), which is located in the inner membrane of the mitochondria in eukaryotic cells.
The mitochondria, often referred to as the powerhouse of the cell, harbors the ETC wherein the high-energy electrons from NADH and FADH2 are passed through a series of electron carriers and pumps that ultimately lead to the production of ATP via oxidative phosphorylation.
The correct answer to the question is d. Electron transport chain.