The molecules of a given mass of a gas have r.m.s. velocity of 200 ${\mathrm{ms}}^{-1} \mathrm{at} {27}^0\mathrm{C} \mathrm{and} 1.0\times {10}^5 {\mathrm{Nm}}^{-2}$ pressure. When the temperature and pressure of the gas are respectively, ${127}^0\mathrm{C} \mathrm{and} 0.05\times {10}^5 {\mathrm{Nm}}^{-2}, \mathrm{the} \mathrm{r}.\mathrm{m}.\mathrm{s}. \mathrm{velocity} \mathrm{of} \mathrm{its} \mathrm{molecules} \mathrm{in} {\mathrm{ms}}^{-1} \mathrm{is}:$

• A

  $100\sqrt{2}$

• B

  $\frac{400}{\sqrt{3}}$

• C

  $\frac{100\sqrt{2}}{3}$

• D

  $\frac{100}{3}$