(单选题)

In Dr. Elzbieta Kurma's experiment, ( ).

A.2 million people aged 60 or older were selected as subjects, who did not have signs or symptoms of dementia.

B.racial or ethnic factors were also considered while making the conclusion.

C.subjects were classified based on their risk of dementia as well as lifestyle factor.

D.scientists proved that genetic alone determine the probability of illness.

参考答案：C

参考解析：

细节题。在第7段Dr. Elzbieta Kuzma and colleagues at the University of Exeter Medical School in England used the UK Biobank to study nearly 200,000 people 60 or older with no signs or symptoms of dementia at the start.从这句话可知英国埃克塞特大学医学院(University of Exeter Medical School)的埃尔兹比塔·库兹马(Elzbieta Kuzma)博士及其同事利用英国生物银行(UK Bio-bank)对近20万名60岁或以上的人进行了研究。根据几十种已知的影响痴呆症的突变，他们的基因风险被分为高、中、低三种。他们还按生活方式因素分组，符合我们的题干，所以C选项符合句意。故本题正确答案选C。

知识点：细节题英语阅读理解通用英语