2 please helpp?

Question

http://i118.photobucket.com/albums/o117/Hannahrae2011/untitled-13.jpg

I dn't understand these at all

Answer 1

This is graph theory, right?

The degree of a vertex is the number of edges incident to the vertex. "Edge" has a slightly different meaning than it would in elementary geometry. For example, in the first figure, BD is an edge in graph theory. In geometry we would call it a diagonal.

In the first figure, both B and F have three edges incident to them, so the answer is C.

So, can you now answer the second problem?