South Africa had 6.5 years of education in 1990, and 10 years by 2015. What was the relativehuman capital per worker in 2015 relative to 1990? Assume returns were 13.4% for primary, 10.1% forsecondary education and 6.8% for post-secondary education.

(a) 0.52

(b) 1.32

(c) 1.52

(d) 3.78