$\sum _{\mathrm{i}=1}^{\mathrm{n}}{\mathrm{d}}^{+}\left({\mathrm{v}}_{\mathrm{i}}\right)=\mathrm{e}$

$\sum _{\mathrm{i}=1}^{\mathrm{n}}{\mathrm{d}}^{-}\left({\mathrm{v}}_{\mathrm{i}}\right)=\mathrm{e}$

$\sum _{\mathrm{i}=1}^{\mathrm{n}}\mathrm{d}\left({\mathrm{v}}_{\mathrm{i}}\right)=\mathrm{e}$

$\sum _{\mathrm{i}=1}^{\mathrm{n}}\mathrm{d}\left({\mathrm{v}}_{\mathrm{i}}\right)=2\mathrm{e}$

15

21

30

6

both G and H has same order

both G and H has same size

both must have same number of vertices with given degree

all of the above

G is a simple graph.

G is a regular graph.

The sum of degree of all vertices in G is 18. 

The sum of degree of all vertices in G is 20. 

a compte graph

a regular graph

both complete and regular graph

neither complete nor regular graph

It has a loop.

It has parallel edges.

It has distinct edges.

It is a multi graph.