Scientist: While studying centuries-old Antarctic ice deposits, I found that several years of relatively severe atmo...

Irina on November 30 at 05:56PM

@nivensdc,

The issue with (C) is that he is not making a universal claim. The conclusion is qualified "so it is clear in this case..," meaning the conclusion only relates to this specific instance of the several-year period in the 1500s. The conclusion is not saying that just because of this finding, it must be true that pollution causes global warming generally.