Which of the Following Gases Have the Highest Average Velocity $\circ$

Which of the following gases have the highest average velocity?

A) diatomic oxygen at 21 ^$\circ$ C
B) diatomic nitrogen at 60 ^$\circ$ C
C) neon at 21 ^$\circ$ C
D) argon at 30 ^$\circ$ C
E) carbon dioxide at 50 ^$\circ$ C