An ideal gas undergoes a cyclic transformation starting from the point $A$ and coming back to the same point by tracing the path $\mathrm{A} \rightarrow \mathrm{B} \rightarrow \mathrm{C} \rightarrow \mathrm{D} \rightarrow \mathrm{A}$ as shown in the three cases above. Choose the correct option regarding $\Delta \mathrm{U}$ :

• Correct answer
  A

  $\Delta \mathrm{U}($ Case-I $)=\Delta \mathrm{U}($ Case-II $)=\Delta \mathrm{U}($ Case-III $)$
• B

  $\Delta \mathrm{U}($ Case-I $)\gt\Delta \mathrm{U}($ Case-III $)\gt\Delta \mathrm{U}($ Case-II $)$
• C

  $\Delta \mathrm{U}($ Case-III $)\gt\Delta \mathrm{U}($ Case-II $)\gt\Delta \mathrm{U}($ Case-I $)$
• D

  $\Delta \mathrm{U}($ Case-I $)\gt\Delta \mathrm{U}($ Case-II $)\gt\Delta \mathrm{U}($ Case-III $)$

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