In this question, we have to find out the wavelength of a light that has a frequency of 4.47*10^14 Hz, and in order to do that, we can use the following formula that shows the relationship between frequency and wavelength:
λ = c/f
Where:
λ = wavelength
c = speed of light, which is a constant value, 2.998*10^8
f = frequency, 4.47*10^14
Now we add these values into the formula:
λ = 2.998*10^8/4.47*10^14
λ = 6.7069*10^-7 meters
The wavelength of this light will be 671 nm, letter B