The Average Kinetic Energy of a Nitrogen Molecule at Room $\degree$

The average kinetic energy of a nitrogen molecule at room temperature (20 $\degree$ C) is:

A) 2 *10-21 J.
B) 4 * 10-21 J.
C) 6 * 10-21 J.
D) 8 * 10-21 J.
E) 1 *10-20 J.