Answer
This graph is not connected. Therefore, this graph is not a tree.
Work Step by Step
For any two vertices in a graph, if there is at least one path which has these two vertices as endpoints, then the graph is connected.
A tree is a graph that is connected and does not have any circuits.
Let's consider vertex D and vertex G. There is no path in this graph such that vertex D and vertex G are endpoints. Therefore, this graph is not connected.
This graph is not connected. Therefore, this graph is not a tree.