A copper rod of 88 cm and an aluminium rod of unknown length have their increase in length independent of increase in temperature. The length of aluminium rod is : $$(\alpha_{Cu}) =1.7 \times 10^{-5} K^{-1} and \alpha_{Al} = 2.2 \times 10^{-5} K^{-1})$$

A

113.9 cm

B

88 cm

C

68 cm

D

6.8 cm