Six stations (S1 to S6) are connected through two bridges (B1 and B2) as shown in the figures below. Initially the forwarding tables are empty. Suppose the following stations transmit frames: S6->S1, S1->S4, S6->S4, S3->S4, S5->S6, S2->S1. What is the forwarding table of B1 after the frames have been transmitted? Si S2 S3 S4 S5 S6 LAN LAN2 LAN3 B1 B2 port 1 port 2 port 1 1 port 2 Station Port Station Port a. None of them b. S6 port2, S1 port1, S3 port1, S5 port 2 S6 port2, S1 port1, S3 port2, S5 port 2 d. S6 port2, S1 port1, S3 port2, S2 port1 e. S6 port2, S1 port1, S3 port2, S5 port 2, S2 port1