Which of the following expressions correctly represents the relationship between the average molar kinetic energy,$\overline{K.E.}$,of $CO$ and $N_2$ molecules at the same temperature?

• A
  $\overline{KE}_{CO} = \overline{KE}_{N_2}$
• B
  $\overline{KE}_{CO} > \overline{KE}_{N_2}$
• C
  $\overline{KE}_{CO} < \overline{KE}_{N_2}$
• D
  Cannot be predicted unless the volumes of the gases are given