In context with the industrial preparation of hydrogen from water gas $(CO + H_2)$, which of the following is the correct statement?

Question

( A ) $H_2$ is removed through occlusion with Pd
( B ) CO and $H_2$ are fractionally separated using differences in their densities
( C ) CO is oxidised to $CO_2$ with steam in the presence of a catalyst followed by absorption of $CO_2$ in alkali
( D ) CO is removed by absorption in aqueous $Cu_2Cl_2$ solution