This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory chain, Subject name: Biochemistry
Hydrogen sulphide acts on which complex of cytochrome oxidase 
Select and explain. 
A. Comlex I, B. Comlex II, C. Comlex III, D. Comlex IV
D: Comlex IV
Answer: D: Comlex IV 
Explanation: Complex IV inhibitors i. Carbon monoxide, inhibits cellular respiration ii. Cyanide (CN-) iii. Azide (N3-) iv. Hydrogen sulphide (H2S)Ref: DM Vasudevan Textbook of Medical Biochemistry, 6th edition, page no: 234