WDM,on the other hand,makes it possible to transmit a largeNumber of（）using theSame fiber,effectivel

[单选]

WDM,on the other hand,makes it possible to transmit a largeNumber of（）using theSame fiber,effectivelySending a “rainbow” ofColors,where there was onlyBefore.

• A、wavelength

• B、wavelengths

• C、color

• D、colors