A.2 B.1.0 C.1.7 D.1.5
A.總配電箱→分配電箱→末級配電箱 B.分配電箱→末級配電箱→總配電箱 C.總配電箱→末級配電箱→分配電箱 D.末級配電箱→分配電箱→總配電箱
A.35 B.40 C.50 D.30