Click the Exhibit button. Given the information shown in the exhibit, when creating 2 DS1 circuits, how many STS ports are used on the VT1.5 matrix at Node 1 as VT circuits and how many are used after using VT tunnels?（）

A.2；0
B.3；2
C.3；5
D.4；0
E.6；0
F.6；2