Consider the internet shown in the follow figure. S$1$ and S$2$ are sending packets to multicast group G$.$ All hosts except S$1$ and S$2$ are members of group G $($when S$1$ is sending the multicast packets, all hosts receive the packets except S$2$; when S$2$ is sending the multicast packets, all hosts receive the packets except S$1).(3$ point$)$