33
Diagram 15 shows an undirected graph.
Which of the following represents the correct set of edges and the sum of degrees?
| | List of vertices | Sum of degrees |
|:---|:---|:---|
| A | {(P, Q), (P, S), (P, T), (Q, R), (Q, R), (Q, Q), (R, S), (S, T), (T, T) | 18 |
| B | {(P, Q), (P, S), (P, T), (Q, R), (Q, Q), (R, S), (S, T), (T, T), (T, T) | 18 |
| C | {(P, Q), (P, S), (P, T), (Q, R), (Q, R), (R, S), (S, T), (T, T) | 16 |
| D | {(P, Q), (P, S), (Q, R), (Q, R), (Q, Q), (R, S), (S, T), (T, T) | 16 |