(1.18) Which of following multiplexing technique transmits digital signals? (a). FDM SDM TDM WDM None of the Above (d). (e). (1.19) Which of following multiplexing technique yields the best resource utilization? (a). (b). CDM FDM TDM WDM All of the above (d). (e). (1.20) The largest portion of the bandwidth for ADSL carries (a). (b). (c). (d). (e). Voice communication Upstream data Control data Downstream data All of the above