<prompt> Normal diffusion of CO2 at rest-20-25 mLminmm Hg50-100 mLminmm Hg100-200 mLminmm Hg300-400 mLminmm Hg  <response>: Ans. d 300-400 mlminmm HgRef: Ganong, 25th edp.640Normal value of DLCO is 25 mLminmm HgDiffusion coefficient of O2 is about 1.23 times that of COSo, Diffusing capacity for oxygen is 251.2330mLminmmHgDiffusion capacity of CO2 is 400 mlminmm Hg 