<prompt> The inhibitor of complex IV of electron transpo chain isBarbituratesAnimycin AHydrogen sulfideDimecaprol  <response>: Complex IV inhibitors i. Carbon monoxide inhibits cellular respiration ii. Cyanide CN- iii. Azide N3- iv. Hydrogen sulphide H2SRef: MN Chatterjea Textbook of Medical Biochemistry, 6th edition, page no: 234 