(a) Apply the BFS algorithm to the graph, beginning at b. Give a list of the BFI (breadth first index) and show the final spanning tree constructed by the algorithm. (b) Apply the DFS algorithm to the graph, also beginning at b. Give a list of the DFI (depth first index) and show the spanning tree constructed by the algorithm. (c) Why do these algorithms for graphs record the BFI (or DFI)