The bright-line spectrum of lithium has a red line with a wavelength of 6.708 x 10⁻11 meters. Calculate the photon energy of this red line.

a) 2.96 x 10⁻¹⁹ J
b) 4.92 x 10⁻¹⁹ J
c) 3.72 x 10⁻¹⁹ J
d) 6.63 x 10⁻³⁴ J