In country x, the average yearly salary of 50-year-olds with 16 years of education is $50,275, while the average yearly salary of 50-year-olds with 12 years of education is $36,265. according to this data, four additional years of education are likely to be correlated with higher future wages of about:
a. 24 percent.
b. 38 percent.
c. 50 percent.
d. 88 percent.