Correct option is C
Explanation-
Iron-sulfur clusters are cofactors found in many enzymes involved in electron transport. They help transfer electrons due to their ability to shift oxidation states.
Option a - NADH – CoQ reductase (Complex I)
It contains Fe–S clusters. It transfers electrons from NADH to CoQ. Fe–S clusters are central here.
Option b - Succinate – CoQ reductase (Complex II)
It contains Fe–S clusters. It transfers electrons from succinate (via FADH2) to CoQ. It has multiple Fe–S centers.
Option c - Cytochrome C oxidase (Complex IV)
It does NOT contain Fe–S clusters. It uses cytochrome a and a3 and copper ions (CuA and CuB) to transfer electrons to oxygen. There is no iron-sulfur groups here.
Option d - CoQH₂ – Cytochrome C reductase (Complex III)
It contains Fe–S clusters. It is also called cytochrome bc1 complex. It uses Rieske Fe–S protein to transfer electrons.
So, the correct answer is option c - Cytochrome C oxidase
