Which is the final electron acceptor in respiration?

Explanation

In aerobic respiration, oxygen functions as the final electron acceptor in the electron transport chain. Electrons are passed along the chain through various complexes and ultimately accepted by oxygen, forming water. This acceptance of electrons by oxygen is vital for establishing the proton gradient that drives ATP synthesis via chemiosmosis. The other options-cytochromes, dehydrogenases, and hydrogen-play roles in electron transfer or proton gradient formation but do not serve as the terminal electron acceptor.