遇到一道想不通的逻辑题，XDF兰书69题

Black Americans are, on the whole, about twice are likely as White Americans to develop high blood pressure. This likelihood also holds for westernized Black Africans when compared to White Africans.

Researchers have hypothesized that this predisposition in westernized Blacks may reflects an interaction between western high-salt diets and genes that adapted to an environmental scarcity of salt.

 Which of the following statements about present-day, westernized Black Africans, if true, would most tend to confirm the researchers' hypothesis?

A.The blood pressures of those descended from peoples situated throughout their history in Senegal and Gambia, where salt was always abailable, are low.

B. The usually high salt consumption in certain areas of Africa represents a serious health problem.

C.Because of their blood pressure levels, most White Africa have markedly decreased their salt consumption.

D.Blood pressures are low among the Yoruba, who, throughout their history, have been situated far inland from sources of sea salt and far south of Sahara salt mines.

E.No significant differences in salt metabolism have been found between those people who have had salt available throughout their history and those who have not.

我对此题最大的疑问就是研究人员的假设是什么，是假设westernized Black 容易得高血压是因为他们的饮食西化了，但是假设的后半段and genes that adapted to an environmental scarcity of salt,我就不懂是什么意思．到底应该选哪个，我做的时候想了半天选了个D,我觉得说在Yoruba这个地方，因为远离盐产地，所以高血压少，但是错了，给出的答案是A,可是我比较了半天觉得A和D要表达的意思其实差不多的，大家说呢？

Researchers have hypothesized that this predisposition in westernized Blacks may reflects an interaction between western high-salt diets and genes that adapted to an environmental scarcity of salt.

西化黑人的predisposition是西方高盐饮食和本身已经适应了缺盐环境基因的共同作用的结果。

首先，西化就确定了了高盐饮食这个条件，要想support，就说这类人的基因如果是适应了不缺盐的环境，结果会怎样怎样就可以了。

B是无关，health problem和文章的论点高血压无关，certain areas of Africa 不明确黑人是否西化。

C是无关，即假设是关于西化黑人的

Damong the Yoruba，该人种是否西化（是否有high-salt diets）？，无关。

E是削弱。