${\mathrm{CH}}_3\mathrm{COCl}+{\mathrm{H}}_2\underset{{\mathrm{BaSO}}_4}{\overset{\mathrm{Pd}}{\to }}{\mathrm{CH}}_3\mathrm{CHO}$

Here BaSO₄ acts as 

The given reaction is known as Rosenmund reduction. Here, palladium (Pd) acts as strong reducing agent that further reduces aldehyde to corresponding alcohol. Barium sulphate acts as catalytic poison that stops from further reduction of aldehyde to alcohol.

Therefore, option (B) is correct.