Consider a connected graph and a spanning tree of it (i.e., a tree that covers all graph nodes). Which of these situations is not possible?

Select one:

a. All of the other listed situations are possible.

b. The tree is a DFS tree but not a BFS tree.

c. The tree is a BFS tree but not a DFS tree.

d. The tree is neither a BFS tree nor a DFS tree.

e. The tree is both a BFS and a DFS tree.