On the average, how do people in late adulthood(mid-60’s) compare to people in early adulthood(mid-20’s) on tests of cognitive performance?

A. 60-year olds perform roughly the same as 20-year olds
B. 60-year olds perform better than 20-year olds
C. 60-year olds perform worse than 20-year olds
D. Research has not compared 60-years olds to 20-year olds