Answer
To make a spanning tree from the original graph, we can use the edges AB, BD, DE, and EC.
Work Step by Step
One characteristic of a tree is the following: If the graph has $n$ vertices, then the graph has $n-1$ edges.
To make a spanning tree from the original graph, we can use the edges AB, BD, DE, and EC. The spanning tree has 5 vertices and 4 edges. Also, the spanning tree is connected and there are no circuits. Therefore, this is a valid spanning tree.
This is one spanning tree, but other spanning trees are possible.