The correct option is D CO is oxidised to CO2 with steam in the presence of a catalyst followed by absorption of CO2 in alkali
On the industrial scale, hydrogen is prepared from water gas according to following reaction sequence.
CO+H2water gas+H2O(steam)catalyst−−−−→CO2+2H22NaOH−−−−−→(alkali)Na2CO3+H2O
From the above, it is clear that CO is first oxidised to CO2 which is then absorbed in NaOH