Answer :
The relationship between wavelength and frequency is given by
[tex]\lambda=\frac{v}{f}[/tex]Where
λ = wavelength
v = speed of light
f = frequency
The speed of light in free space is 2.998×10⁸ m/s
For the given case, the wavelength is 442×10⁻⁹ m
So, the corresponding frequency of this color of light is
[tex]f=\frac{v}{\lambda}=\frac{2.998\times10^8}{442\times10^{-9}}=6.79\times10^{14}\: Hz[/tex]Therefore, the frequency of this color of light is 6.79×10¹⁴ Hz
Option A is the correct answer.