d
$v_{r m s}=\sqrt{\frac{3 R T}{m}}$
$\bar{v}=\sqrt{\frac{8 R T}{\pi m}}=\sqrt{\frac{2.5 R T}{m}}$
and $v_{p}=\sqrt{\frac{2 R T}{m}}$
From these expressions, we can see that
$v_{p}<\bar{v}$
Again, $v_{r m s}=v_{p} \frac{\sqrt{3}}{2}$
and average kinetic energy of a gas molecule
$E_{k}=\frac{1}{2} m v_{rm s}^{2}$
$E_{k}=\frac{1}{2} m\left(\sqrt{\frac{3}{2}} v_{y}\right)^{2}=\frac{1}{2} m \times \frac{3}{2} v_{p}^{2}=\frac{3}{4} m v_{p}^{2}$