Answer
This graph has six vertices and two bridges. The edge BE and the edge DF are bridges.
Work Step by Step
In a connected graph, for any pair of vertices, there is at least one path with these two vertices as the endpoints of the path. If removing an edge makes the graph disconnected, then that edge is called a bridge.
This graph is a connected graph. However, if we remove the edge BE or the edge DF, the graph will be disconnected. The edge BE is a bridge and the edge DF is a bridge. However, no other edge is a bridge, since we can remove any other edge without making the graph disconnected.
This graph has six vertices and two bridges. The edge BE and the edge DF are bridges.
