The Orsat apparatus for flue gas analysis will show which of the following sets of gases in the engine exhaust

Question

When a hydrocarbon fuel burns in insufficient air, the Orsat apparatus for flue gas analysis will show which of the following sets of gases in the engine exhaust                       

(a) CO₂, N₂ and O₂

(b) CO, CO₂, N₂ and O₂

(c)CO, CO₂ and N₂

(d) CO₂, CO, N₂, O₂ and H₂O