$\begin{aligned}
& \mathrm{A} \rightarrow \mathrm{P} \propto \frac{1}{\mathrm{~V}} \
& \Rightarrow \mathrm{PV}=\text { constant } \
& \Rightarrow \mathrm{nRT}=\text { const. } \Rightarrow \mathrm{T}=\text { const. }
\end{aligned}HenceIsothermalIIIB\rightarrowIV\mathrm{W} \neq 0, \Delta \mathrm{U} \neq 0, \Delta \mathrm{Q} \neq 0[onlyisobaric]\mathrm{C} \rightarrow \mathrm{I} \Delta \mathrm{Q}=0Adiabatic\mathrm{D} \rightarrowIIw=0$ Isochoric III, IV, I, II