Which of the Following Is an Example of Cohort Effects

Which of the following is an example of cohort effects?

A) that individuals tend to share the same party identification as their parents
B) that people with high agreeableness are more likely to favor economic policies that help the disadvantaged
C) that, until the 1970s, relatively few native white southerners identified with the Republican Party
D) the failure of President Clinton to enact health care reform in 1994
E) the increasing ideological polarization in Congress