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
The inhibitor of complex IV of electron transpo chain is 
Select and explain. 
A. Barbiturates, B. Animycin A, C. Hydrogen sulfide, D. Dimecaprol
C: Hydrogen sulfide
Answer: C: Hydrogen sulfide 
Explanation: Complex IV inhibitors i. Carbon monoxide inhibits cellular respiration ii. Cyanide (CN-) iii. Azide (N3-) iv. Hydrogen sulphide (H2S)Ref: MN Chatterjea Textbook of Medical Biochemistry, 6th edition, page no: 234