In the electron transport chain during terminal oxidation,the cytochrome,which donates electrons to $O_2$ is

Which of the following is not a component of complex-$IV$ (cytochrome-$c$ oxidase)?

During the oxidation of $NADH + H^+$,through which complex do electrons $NOT$ pass?

$A$ : Cytochrome $c$ is a peripheral protein.
$R$ : It is found attached on the perimitochondrial space side of the inner mitochondrial membrane.

Given below are two statements.
$Statement-I$: During aerobic respiration, $ETS$ releases energy in a stepwise manner to prevent damage to cells.
$Statement-II$: During aerobic respiration, $ETS$ provides water molecules.
In the light of the above statements, choose the correct answer from the options given below.

“Mitchell's chemiosmotic theory” belongs to