In the reported figure, there is a cyclic process ABCDA on a sample of 1 mol of a diatomic gas. The temperature of the gas during the process $\mathrm{A} \rightarrow \mathrm{B}$ and $\mathrm{C} \rightarrow \mathrm{D}$ are $\mathrm{T}_1$ and $\mathrm{T}_2\left(\mathrm{~T}_1>\mathrm{T}_2\right)$ respectively.

Choose the correct option out of the following for work done if processes BC and DA are adiabatic.