Identify P,Q,R and S in the given diagram of electron transport system.
A. `{:(P,Q,R,S),("Matrix","Outer chamber",FMNH_(2),NADH_(2)):}`
B. `{:(P,Q,R,S),("Inter-membrane space","Matrix",NaDH +H^(+),NAD^(+)):}`
C. `{:(P,Q,R,S),("Inter-membrane","Cristae",NAD^(+),NADH+H^(+)):}`
D. `{:(P,Q,R,S),("Cristae","Outer chamber",NADH+H^(+),NAD^(+)):}`
