Calculate the Magnitude of the Potential Energy for the Interaction

Calculate the magnitude of the potential energy for the interaction of two co-linear hydrogen fluoride, HF, molecules whose centres are separated by 5.0 Å. The dipole moment of a hydrogen fluoride molecules is 1.91 D.

A) 1.9 * 10^-21 J
B) 12 *10^-22 J
C) 5.8 * 10^-21 J
D) 2.9 * 10^-21 J