which of the following contributed most significantly to the population trend in pre-columbian mexico described in the excerpt?

Which of the following comparisons is true? a: high school tests generally cover more material than college exams. b: your college curriculum is more fixed and standardized than your high school curriculum. c: you get more personal attention in class from your college professors than from your high school teachers. d: college professors usually don't review test material in class the way high school teachers do.