Which of the Following Best Illustrates the Effects of Swing

Which of the following best illustrates the effects of swing states on the campaigns for president during the general election?

A) Both Obama and Romney spent more than 99 percent of their television advertising budgets for ads in swing states.
B) Swing states represent approximately 20 percent of the Electoral College vote.
C) Of the states with the largest Electoral College delegations, only California and Texas were regularly visited by presidential candidates in the last three election cycles.
D) Both Obama and Romney spent more than 90 percent of their total advertising budgets on negative ads.