Please help in the name of steven universe and the command of white diamond

What do states primarily use their reserved powers to regulate? a. services related to national citizenship b. issues that affect day-to-day life for state residents c. issues involving taxation d. issues that affect states' interaction with the federal government

Why didn’t the united states participate in the league of nations? the u.s. senate did not want the country to join. president wilson did not want the country to join. the league of nations was only for european countries. the league of nations had failed to prevent world war 1

Powers of states the first letter of the answer is r.