Which Statement Best Describes Kaufman's (2001) Findings on the Pattern

Multiple Choice

Which statement best describes Kaufman's (2001) findings on the pattern of IQ change from young adulthood though old age generated by cross-sectional studies?

A) IQ scores peak in young adulthood (age 20-30) and decline steadily through middle age (40-50) and old age (80-90) .
B) IQ scores rise gradually until middle age (age 40-50) then decline slowly until old age (around 80) when the decline accelerates.
C) IQ scores remain fairly constant across the lifespan.
D) IQ scores increase gradually between young adulthood (age 20-30) and old age (80-90) .