<prompt> Concentration of methemoglobin to cause cyanosis-5 gmdl2 gmdl1.5 gmdl12 gmdl  <response>: Ans. c 1.5gmdlRef: Ganong, 25th edp.647The level of methemoglobin producing cyanosis is 1.5gmdlIf deoxyhemoglobin reduced Hb is 5.0gdL or greater, cyanosis appears 