Karloss Has Administered an IQ Test to a Large Sample

Karloss has administered an IQ test to a large sample of people representative of the general population. If his results are consistent with those discussed in your textbook, he should find the greatest difference between which two groups?

A) Upper-class and lower-class subjects of the same ethnicity
B) Males and females of the same socioeconomic class
C) African Americans and European Americans of the same socioeconomic class
D) Asians and Hispanics of the same socioeconomic class