A monoatomic ideal gas, initially at temperature $$T_1$$ is enclosed in a cylinder fitted with a frictionless piston. The gas is allowed to expand adiabatically to a temperature $$T_2$$ by releasing the piston suddenly. If $$l_1$$ and $$l_2$$ are the lengths of the gas column, before and after the expansion respectively, then the value of $$\frac{T_1}{T_2}$$ will be:

A

$$\left(\frac{l_1}{l_2}\right)^{2/3}$$

B

$$\left(\frac{l_2}{l_1}\right)^{2/3}$$

C

$$\frac{l_2}{l_1}$$

D

$$\frac{l_1}{l_2}$$