Which factor is an important consideration when interpreting the gap in educational achievement between U.S. students and other students around the world?
a) There is a broader diversity of students in the United States compared to the student bodies of other countries.
b) U.S. parents and students do not care as much about education as do parents and students from other countries.
c) There are low literacy rates for female U.S. students.
d) U.S. students spend more time in classes but get less intensive instruction.