A copper rod of $88 \mathrm{c}\mathrm{m}$ and an aluminum rod of unknown length have their increase in length independent of increase in temperature. The length of aluminum rod is $\left({\alpha }_{\mathrm{C}\mathrm{u}}=1.7\times {10}^{-5} {\mathrm{K}}^{-1}\mathrm{a}\mathrm{n}\mathrm{d}{\alpha }_{\mathrm{Al}}=2.2\times {10}^{-5}{\mathrm{K}}^{-1}\right)$

• A

  $6.8 \mathrm{c}\mathrm{m}$
• B

  $113.9 \mathrm{c}\mathrm{m}$
• C

  $88 \mathrm{c}\mathrm{m}$
• Correct answer
  D

  $68 \mathrm{c}\mathrm{m}$

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