Which of the following processes takes place in the mitochondria?

How many complexes are involved in the electron transport system $(ETS)$ in mitochondria?

$A$ : In cellular respiration,$ETS$ electron movement is a downhill journey.
$R$ : Electrons move from high redox potential to low redox potential.

Oxidative phosphorylation is

$A$ : $2,4-DNP$ $(2,4-Dinitrophenol)$ is an uncoupling agent of $ETS$.
$R$ : It is soluble in lipids.

Match the following columns regarding the Electron Transport System $(ETS)$:

Column-$I$ ($ETS$ Complex)	Column-$II$ (Name of Complex)
$P$. Complex-$I$	$I$. Cytochrome $c$ oxidase complex
$Q$. Complex-$II$	$II$. Cytochrome $bc_1$ complex
$R$. Complex-$III$	$III$. $ATP$ synthase complex
$S$. Complex-$IV$	$IV$. $FADH_2$ dehydrogenase complex
$T$. Complex-$V$	$V$. $NADH$ dehydrogenase complex