Ideal gas at pressure P undergoes free expansion from its initial volume of 1.01 litre to 10.1 litre. The final pressure of the gas is?

• A

  $\mathrm{P}\left(10\right)\mathrm{\gamma }$

• B

  $\frac{\mathrm{P}}{{10}^{\mathrm{\gamma }}}$

• C

  10 P

• D

  $\frac{\mathrm{P}}{10}$