22.如下圖所示電路,試問 a、b 兩端的諾頓(Norton)等效電流 IN 及等效電阻 RN 分別為何?(A)IN =10A,RN =8Ω (B)IN =10A,RN =6Ω (C)IN =5A,RN =8Ω (D)IN =5A,RN =6Ω。