An ideal gas is subjected to a cyclic process $A B C D$ as depicted in the $p-V$ diagram given below
Which of the following curves represents the equivalent cyclic process?

$A \rightarrow B \rightarrow C \rightarrow D \rightarrow A$ is clockwise process. During $A \rightarrow B$, pressure is constant and $B \rightarrow C$, process follows $p \propto \frac{1}{V}$, it means $T$ is constant. During process $C \rightarrow D$, both $p$ and $V$ changes and process $D \rightarrow A$ follows $p \propto \frac{1}{V}$ which means $T$ is constant.
Hence, from above data it is clear that equivalent cyclic process is