Nuclear Fusion Is Achieved by Fusing Hydrogen Isotopes at High

Nuclear fusion is achieved by fusing hydrogen isotopes at high temperatures.The average kinetic energy of deuterium,one of the isotopes of hydrogen,at this temperature is 2.1 *10^-14 J.What is the temperature?

A) 8.5 * 10⁸ K
B) 1.5 * 10⁹ K
C) 2.6 * 10⁹ K
D) 1.0 * 10⁹ K
E) 4.1 * 10⁹ K