N molecules, each of mass m of gas A and 2N molecules each of mass 2m of gas B are contained in the same vessel which is maintained at temperature T. The mean square velocity of molecules of .B type is denoted by ${\mathrm{v}}^2$ and the mean square velocity of A type is denoted by ${\mathrm{\omega }}^2$, the $\frac{{\mathrm{\omega }}^2}{{\mathrm{v}}^2}$is 

• A

  2

• B

  1

• C

  $\frac{1}{2}$

• D

  $\frac{2}{3}$