Given below is information about a network. Choose one of the following three options: the network is definitely a tree; the network is definitely not a tree; the network may or may not be a tree $($more information is needed$).$ Accompany your answer with a brief explanation for your choice.

The network has redundancy $R=1.$

Choose the correct answer below.

A$.$ The network may or may not be a tree because the number of circuits is unknown.

B$.$ The network may or may not be a tree because the number of bridges is unknown.

C$.$ The network is definitely a tree because $R=1$ means that the network has $N$ vertices and $N+2$ edges.

D$.$ The network is definitely not a tree because $R=1$ means that the network has $N$ vertices and $N+2$ edges.

E$.$ The network is definitely a tree because $R=1$ means that the network has $N$ vertices and $N$ edges.

F$.$ The network is definitely not a tree because $R=1$ means that the network has $N$ vertices and $N$ edges.