Concept:When a gas expands and does work against a constant pressure, the work done is the product of the pressure and the increase in volume: W=PΔV.Explanation:Pressure, P=105Nm−2.Initial volume, V1=0.6m3.Final volume, V2=1.2m3.The change in volume is ΔV=V2−V1=1.2−0.6=0.6m3.Substitute into the work formula: W=PΔV=105×0.6.So, W=6.0×104Nm.Since 1Nm=1J, we have W=6.0×104J.Answer:The work done is 6.0×104J; the correct option is D.