Answer:
B. There should be a limit on how much can be spent for political campaigns
Explanation:
Answer choice B is the most logical because a,c,and d are all in the format of a supporting detail, when you look at B, you can tell that it is simply a statement.
Answer choice B looks more like a topic sentence in an essay
Besides that point, If you look closely, all of the other answer choices include key words such as <em>would</em> and <em>could</em>. This means that the something would have to happen <em>before</em> the latter option could.