Why do you think researchers sometimes find a positive relationship between the unemployment rate and college enrollment rates? A) The opportunity cost of attending college rises during economic booms, leading to higher college enrollment rates. B) The opportunity cost of attending college rises during recessions, leading to higher college enrollment rates. C) The opportunity cost of attending college falls during recessions, leading to higher college enrollment rates. D) The opportunity cost of attending college falls during economic booms, leading to higher college enrollment rates.