This answer is incorrect because it summarizes the context of the stimulus. It explains why some predicted that global warming would lead to more frequent and intense tropical storms: tropical storms are more likely to form over warm oceans.

This misstates the conclusion. The correct conclusion is that global warming will probably not result in more frequent and intense storms. However, this answer claims that the conclusion is about global warming not being the only factor affecting storm frequency and intensity.

This isn’t an argument made in the stimulus. The geographer doesn’t consider what would be required to reverse global warming; she only disputes one prediction about the effects global warming may have. Since this claim isn’t made in the stimulus, it can’t be the main conclusion.

This addresses a premise, not the main conclusion. The geographer uses global warming's effect on wind flow to support her conclusion that global warming won't lead to more intense and frequent storms. Since this claim is supporting evidence, it can't be the main conclusion.

This accurately captures the main conclusion: the geographer believes that predictions about global warming’s effect on tropical storms were likely incorrect. The answer summarizes this by stating that global warming probably won't lead to more frequent and intense storms.