Two graphs, labelled Graph 1 and Graph 2, are shown below.

The sum of the degrees of the vertices of Graph 1 is

- two less than the sum of the degrees of the vertices of Graph 2.
- one less than the sum of the degrees of the vertices of Graph 2.
- equal to the sum of the degrees of the vertices of Graph 2.
- two more than the sum of the degrees of the vertices of Graph 2.