Which of the following is an example of evidence that points to how social factors can explain health disparities across subpopulations?

A. Research by Currie, Greenstone, and Moretti that studied environmental "superfund" sites to isolate environmental factors, which found that children born after the environmental cleanup were less likely to become ill than those born before
B. Research by David Williams that showed a link between the day-to-day stress of racism and discrimination on stress-related disease among African-Americans
C. Studies that suggest that different cultural values and norms related to hygiene can explain different health indicators across subpopulations
D. Studies that link genetic factors to the incidence of certain diseases to subpopulations, such as sickle-cell anemia among African-Americans