The spanning tree of the graph is like a subgraph that carries all vertices which is similar to a tree. Further, it is analysed that a graph carries many spanning trees which will complete a graph that contains four vertices.

In a bridge network, there are a number of LANs which are joined in a spanning tree. In this, the root bridge has the least number with data units being the shortest. Here the port conflicts are solved with the lower index value. In this, the bridge close to the root is strong with preference given to the lowest serial.

Now in a LAN network, select which sequence shows depth-first in terms of the spanning tree of bridges?