This Result Was Concluded from Comparisons of Women Born in 1910-1930

This result was concluded from comparisons of women born in 1910-1930 and women born between 1960-1980. Based on this information, the criticism you would be likely to make would be that

A) this is not a valid result because men were not included.
B) longitudinal research doesn't work well when looking at IQ data.
C) cohort effects are likely to account for the differences.
D) whoever conducted this study doesn't like older women.