A Study Conducted by Economists Alan Krueger and Stacy Dale

A study conducted by economists Alan Krueger and Stacy Dale concluded that

A) earnings of college graduates were mostly unrelated to the toughness of their colleges' admissions standards.
B) students from low-income families had little or nothing to gain by being admitted to a college that has tough admissions standards.
C) earnings of college graduates were only slightly higher than earnings of high school graduates.
D) people who attended colleges where sports are important have higher incomes than people who attended colleges where sports are not important.