According to given p−V diagram, As we know that work is equal to area under p−V graph.
∴WA>WB>WC>WD and by using 1st law of thermodynamics,ΔQ=ΔU+ΔW Here, internal energy, ΔU=0 ∵ Initial and final positions are same. ∴ Heat (ΔQ) sequence will be ΔQA>ΔQB>ΔQC>ΔQD Hence, QA−QD=WA−WD