A Collection of Atoms Has 20% of the Sample in a State

Multiple Choice

A collection of atoms has 20% of the sample in a state 5.9 eV above the ground state. If these emit coherent radiation, what is the wavelength of the laser light produced? (c = 3.00 × 10⁸ m/s, h = 6.626 × 10^-34 J ∙ s, 1 eV = 1.60 × 10^-19 J)

A) 210 nm
B) 91 nm
C) 340 nm
D) 34 nm