A

The average kinetic energy (KE) of the molecules of an ideal gas can be expressed using the formula:
$$ KE_{avg} = \frac{3}{2} k T $$
where k is the Boltzmann constant (1.38 x 10^-23 J/K) and T is the absolute temperature in Kelvin. For an ideal gas at absolute temperature TK, the average kinetic energy of the molecules is directly proportional to the temperature.
Therefore, the average kinetic energy due to translational motion of most molecules at absolute temperature TK is given by the formula above.