What Is the Frequency $\nu$ , in Hz) of the Photons Emitted by a He-Ne

What is the frequency ( $\nu$ , in Hz) of the photons emitted by a He-Ne laser with a wavelength ( $\lambda$ ) of 632.8 nm?

A) 4.738 * 10⁵ Hz
B) 1.897 *10² Hz
C) 1.897 *10¹¹ Hz
D) 4.741 *10¹⁴ Hz
E) 1.897 * 10¹⁴ Hz