If a heat engine and a refrigerator are working between the same two temperatures $T_1$ and $T_2\left(T_1>T_2\right)$, then the ratio of efficiency of heat engine to coefficient of performance of refrigerator is

• A

  $\frac{\left(\mathrm{T}_1-\mathrm{T}_2\right)}{\mathrm{T}_1 \mathrm{~T}_2}$
• B

  $\frac{\left(\mathrm{T}_1+\mathrm{T}_2\right)}{\mathrm{T}_1 \mathrm{~T}_2}$
• Correct answer
  C

  $\frac{\left(\mathrm{T}_1-\mathrm{T}_2\right)^2}{\mathrm{~T}_1 \mathrm{~T}_2}$
• D

  $\frac{\left(T_1+T_2\right)^2}{T_1 T_2}$

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