A because that is the answer
The answer would be a radio wave
You need to use Planck's law:
E = h·υ = (h·c)/λ
Without making all the calculations, a fraction is bigger than another when the denominator is smaller. Therefore you need to find the smallest wavelength (λ) which is 450nm.
You could also be helped by colors: in order of decreasing energy, you have blue - green - yellow - red.
In any case, the correct answer is a).
Divide CFU of Dilution. Divide the CFU of the dilution (the number of colonies you counted) by the result from step 4. For this example, you work out 46 ÷ 1/1000, which is the same as 46 x 1,000. The result is 46,000 CFU in the original sample.
