The three thermodynamic states $\mathrm{P}, \mathrm{Q}$ and R . of a system are connected by the paths shown in the figure given on the right. The entropy change in the processes $\mathrm{P} \rightarrow \mathrm{Q}, \mathrm{Q} \rightarrow \mathrm{R}$ and $\mathrm{P} \rightarrow \mathrm{R}$ along the paths indicated are $\Delta S_{P Q}$, $\Delta S_{Q R}$ and $\Delta S_{P R}$ respectively. If the process $\mathrm{P} \rightarrow \mathrm{Q}$ is adiabatic and irreversible, while P $\rightarrow \mathrm{R}$ is adiabatic and reversible, the correct statement is

• A

  $\Delta S_{Q R} \gt 0$
• B

  $\Delta S_{P R} \gt 0$
• Correct answer
  C

  $\Delta S_{Q R} \lt 0$
• D

  $\Delta S_{P Q} \lt 0$

Hence, the correct answer is option: 'C'.