In ETC at which complex ATP is not formed -
High-Yield Explanation
Ans. is 'b' i.e., Succinate CoQ reductase Complex (I-IV) & Sites (I-III of ATP formation) in ETCComplex I: NADH CoQ-reductasePermit ATP formation (Site I)Act as proton pumpComplex II: Succinate CoQ reductaseNo ATP formComplex III; CoQ - cytochrome - C reductasePermit ATP formation (Site II)Act as proton pumpComplex IV: Cytochrome C oxidasePermit ATP formation (Site III)Act as proton pump