OG5 阅读 Q45

Choice C is the best answer. The purpose of Maguire's study of the mental athletes was to try to determine what it is that makes them so good at memorization, and in particular if they have structurally different brains than people without such extraordinary memorization skills or if they have normal brain structures but use them in unusual ways. This is supported in lines 33-37("World ...possess"), which state that Maguire and her team "wanted to find out if the memorizers' brains were—like the London cabbies'—structurally different from the rest of ours, or if they were somehow just making better use of memory abilities that we all possess."
Choice A is incorrect because the study was an attempt to compare the brains of mental athletes to the brains of the general population, not to compare the use of different brain structures in memorization and navigation. Choices B and D are incorrect because the passage makes it clear that it was not known if mental athletes have unusual brain structures; finding out if they do was actually one of the goals of the study.