The r ms speed of the molecules of a ideal gas which is at a pressure $10^5 \;m^{-2}$ & density $45\;kgm^{-3}$ is _________

Question

$(A)\; 100 m/s \\ (B) \; 150\;m/s \\ (C)\;200\;m/s \\ (D)\;250\;m/s$