Which of the Following Statements Is True About Herrnstein and Murray's

Which of the following statements is true about Herrnstein and Murray's arguments in The Bell Curve?

A) Whites score lower than blacks on traditional IQ tests when socioeconomic status (SES) is taken into account.
B) An analysis of IQ differences between whites and blacks demonstrated that there were basic genetic differences between the two races.
C) Middle- and upper-SES blacks score higher than middle- and upper-SES whites.
D) Intelligence differences between blacks and whites can be attributed to environmental differences alone.