OG4 阅读 Q48

Choice C is the best answer. In lines 68-71("Another...C.E"), the author states, "Another possible candidate—both in terms of timing and geographical location—is Ecuador's Quilotoa, estimated to have last erupted between 1147 and 1320 C.E." The phrase "another possible candidate" implies that the scientists believe that in the Middle Ages a different volcanic eruption, such as an eruption from the volcano Quilotoa, could have been responsible for the onset of the Little Ice Age.
Choices A, B, and D are incorrect because the phrase "another possible candidate" does not imply the frequency or effects of volcanic eruptions, or that some volcanoes have large calderas.