Given the following statements: (a) Frequency Division Multiplexing is a technique that can be applied when the bandwidth of a link is greater than combined bandwidth of signals to be transmitted. (b) Wavelength Division Multiplexing (WDM) is an analog multiplexing Technique to combine optical signals. (c) WDM is a Digital Multiplexing Technique. (d) TDM is a Digital Multiplexing Technique. Which of the following is correct? (A) (a), (b), (c) and (d) are true. (B) (a), (b), (c) and (d) are false. (C) (a), (b) and (d) are false; (c) is true. (D) (a), (b) and (d) are true; (c) is false.