What is the most serious threat to internal validity in nonequivalent control group design?

If the U.S. successfully pressures China to decrease its human rights violations, despite the fact that China does not want to, the U.S. is exerting __________

a. force b. legitimacy c. sovereignty d. power

Which of the following individuals is/are eligible to participate in a Republican precinct convention held on the evening of primary election day?

a) a person who voted during the day in the Democratic primary election b) a person who voted during the day in the Republican primary election c) a registered voter who failed to vote on primary day d) All of the above. e) None of the above.