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 would and could. This means that the something would have to happen before the latter option could.