The Wavelength of the Blue Light Given Off by a Mercury

The wavelength of the blue light given off by a mercury vapor street lamp is 436 nm.What is the frequency of this light in hertz (s^-1) ?

A) 6.88 x 10⁵ s^-1
B) 6.88 x 10¹⁴ s^-1
C) 1.45 x 10^-6 s^-1
D) 1.45 x 10^-13 s^-1
E) 1.31 x 10² s^-1