Problem 2.4 - page 30. The line graph of a graph G = (V,E) is the graph L(G) = (E, F) whose vertex set is E and whose edge set is F={{e, f} CE enf0} (a) Prove that if G is connected and regular then L(G) is Eulerian (b) Prove that if G is Eulerian then L(G) is also Eulerian (c) If the line graph of a graph G is Eulerian, must G be Eulerian?