In Electron transport chain ultimate electron acceptor is:

Correct Answer: A. Oxygen

The correct answer is:
A. Oxygen
Explanation:
In the Electron Transport Chain (ETC), oxygen serves as the ultimate (final) electron acceptor. Here’s how it works:
Electrons are passed along a series of protein complexes and coenzymes embedded in the inner mitochondrial membrane.
As electrons move through the chain, they release energy, which is used to pump protons (H⁺) across the membrane, creating a proton gradient.
At the end of the chain, electrons are transferred to oxygen, which combines with protons to form water: O2+4e^−+4H^+→2H2O