C) hope this helps may not be right :4
sulfur and dihydrogen monoxide
D. The discoveries confirmed many but not all of the classifications that were based on observable traits, and scientists revised classifications when necessary.
Answer: Protons contribute towards making ATP by producing proton-motive force that provides energy for ATP synthesis.
Explanation: In the respiratory chain, the transfer of electrons from one complex to another is accompanied by pumping of protons out of the matrix. This creates a difference in proton concentration and separation of charge across the mitochondrial inner membrane. The electrochemical energy inherent in this difference in proton concentration called proton-motive force is used to drive ATP synthesis as protons flow back passively into the matrix through a proton pore.