An engineer needs to design a four-wave WDM system using a displaced dispersion fiber that has a zero dispersion point at 1,550 nm. The four wavelengths must be in the band between 193.1 and 194.1 THz in a 100 GHz grid (the minimum spacing between wavelengths must be 100 GHZ). (a) What should be the criterion used to allocate these wavelengths so that none of the components of the four-wave mix does not match any wavelength of the original signal used in the transmission? (b) Propose a possible allocation scenario for these four wavelengths where all the generated wavelengths do not coincide with the original frequencies and determine all the generated frequencies.