The relation between root mean square speed $(v_{rms})$ and most probable speed $(v_{p})$ for the molar mass $M$ of oxygen gas molecule at the temperature of $300\, K$ is:

• A
  $v_{rms} = \sqrt{\frac{2}{3}} v_{p}$
• B
  $v_{rms} = \sqrt{\frac{3}{2}} v_{p}$
• C
  $v_{rms} = v_{p}$
• D
  $v_{rms} = \sqrt{\frac{1}{3}} v_{p}$