When a change in the dependent variable could be due to how participants were picked or assigned to groups, __________ is a threat to internal validity

For which of the following would the Supreme Court most likely apply an intermediate standard of review to determine whether the policy is an unconstitutional violation of the equal protection clause?

a. having a different minimum age for men to marry than for women to marry b. prohibiting those over 70 years old from working in law enforcement c. prohibiting gays and lesbians from serving in the military d. requiring government contractors to have a racially diverse workforce--

British colonial rule introduced

a. a series of changes to undevelop Nigeria. b. the idea of "cash crops.". c. a single Nigerian colony. d. Options A, B, and C are true. e. None of the above is true.