参考答案：D

解析：[听力原文] About 10 percent of Europe’s present-day population seems to be resistant to HIV -- a significantly higher proportion than on other continents. Researchers have traced this immunity to a genetic mutation that seems to have appeared some 2,500 years ago, and that protects white blood cells against penetration by HIV. From the mid-14th century through the 17th century the prevalence of the mutation increased, in tandem with repeated outbreaks of the plague. The researchers suggest that the mutation protected against the disease, which culled the population of people who lacked it.

[分析]： 逻辑关系的找寻和判断。 原文一开始便指出当今欧洲有大约10％的人口对HIV有免疫力。然后指出Researchers have traced this immunity to a genetic mutation that seems to have appeared some 2,500 years ago，and that protects white blood cells against penetration by HIV. 即经研究发现该免疫力来自一种基因突变，该突变在2500年前便已产生，这种基因突变可保护白血球免于 HIV的穿透。由此可见，D项与原文相符，是正确答案。[解题关键] 掌握篇章结构形成的意义上的内在逻辑，支持性细节往往具体说明或解释主题。