补充材料59, needs you help!

59, Black Americans are, on the whole, about twice as 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 reflect an interaction between western high-salt diets and genes that adapted to an environmental scarcity of salt.

Which of the following statement about present day westernized black africans 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, wheere salt was always available, are low.

The key is A, but what’s the line of reasoning between them? Thanks.