If the Bond in Carbon Monoxide Is Modeled as a Harmonic

If the bond in carbon monoxide is modeled as a harmonic oscillator the force constant is 1860 N m^-1, and the reduced mass is 6.86 amu. What is the energy of the ground vibrational state of CO?

A) 1.35´10^-21 J
B) 2.71´10^-21 J
C) 3.53´10^-21 J
D) 2.13´10^-20 J
E) 4.26´10^-20 J