For me it's between A and D... I'm gonna go with A because it proves the hypothesis by taking into account the reciprocal of what's being said.

So, A for me.

A by POE for me

I think, the argument claims that the interaction, not from genes only, btw high-salt diets and genes...is responsible for the high blood pressure

And E confirms this hypothis by saying that there is no significant difference in salt metabolism.... E means that difference in salt methobolism is not considerable, and therefor it confirms the hypothis.

What do you think?
_________________

Find out what's new at GMAT Club - latest features and updates

Let be confident attaching with your choice the explaination, no matter what it is wrong or correct!

And pls comment on my reasoning! Welcome all the comments!
_________________

Find out what's new at GMAT Club - latest features and updates

Hehe, thank you, your reasoning points out my weakness that almost quicly swep my eyes on the text. Only when reviewing your reasoning, I recognized "White african". My god!

Anyway, I got the point!
_________________

Find out what's new at GMAT Club - latest features and updates

I think you missing the point of what a westernized Black African is. You support 2 is comparing Black Africans that came to America to White Africans that are still in Africa. So both the westernized Black Africans and White Africans genes probably have adapted to low salt levels of Africa, but only the westernized Black Africans are exposed to the high salt diet in America while the White Africans are still in Africa with low salt diets.

Regradless of where they're at (i.e. In America or in Africa with American culture) The westernized Black Africans are exposed to high salt diets and White Africans are not.

The Black Americans are originally from Africa. So there genes have adapted to low salt.
The westernized Black Africans are from Africa. So there genes have adapted to low salt.
White Africans are from Africa. So there genes have adapted to low salt.
White Americans are not from Africa. So there genes have NOT adapted to low salt.

The Black Americans are in America. So they have high salt diets.
The westernized Black Africans use westernized culture. So they have high salt diets.
White Africans are in Africa. So they have low salt diets.
White Americans are in America. So the have high salt diets.

The conlusion is that if you go from low salt to high salt you will develop high blood pressure.

The only groups going from low salt to high salt are the Black Americans and the westernized Black Africans.

Statement A help to confirm this by stating that the Black Africans from regions where salt was originally high now have low blood presssure.

Statement C indicates that White Africans have high blood pressure. But White Africans have never been introduced to high salt diets. So this weakens the researchers hypothesis.

you may have a point, but don't you think the question is asking us to look into statements about present-day, westernized Black Africans?
Which of the following statements about present-day, westernized Black Africans
I think there are different ways of strengthening the researcher's hypothesis.But the question is directed towards present-day, westernized Black Africans.
C is talking about cause/effect relationship between White Africans and their salt consumption.

OA is A.
Thanks

why is D wrong..?

(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 Saharan salt mines.

In order for the researchers hypothesis to hold true there has to be an environmental scarcity of salt in Africa. This contradicts the hypothesis by stating that there are multiple sources of salt in Africa (sea salt and salt mines).