____, and ____ are arrayed in the shape of Kun Trigram (☷). A: The Six Eastern Palaces B: The three halls C: The Six Western Palaces D: the three gates

Click the Exhibit button.  Which type of multiplexer is shown in the exhibit？（） A:  Thin Film filter B:  Fiber Bragg Grating C:  Arrayed Wave Guide D:  Erbium fiber amplifier