Henry Goddard's Argument on the Genetic Inferiority of Certain Groups

Henry Goddard's argument on the genetic inferiority of certain groups was further reinforced when

A) a series of new studies comparing identical twins separated from birth proved the genetic basis of intelligence.
B) case studies of families from a small Midwestern city showed how the transmission of intelligence was traced to a genetic basis.
C) intelligence testing found that people from Eastern Europe actually had higher IQ scores than those from Northern Europe.
D) African Americans and other racial minorities scored lower than Whites in large-scale Army intelligence testing.