Final answer:
Voter participation is decreasing in the United States, Japan, and Great Britain, where lack of compulsory voting and complex election frameworks contribute to lower turnout compared to other democracies.
Step-by-step explanation:
Voter participation is decreasing in D. all of the above: the United States, Japan, and Great Britain. In the United States, about 54% of the voting-age population turns out to vote, which lags behind countries like Germany and Sweden. In Great Britain, there has been a characterizing trend of snap elections and non-fixed election dates, which may affect voter turnout. Japan also experiences low political participation, similar to many industrialized countries. Reasons for low voter turnout may include lack of compulsory voting laws, as seen in countries with higher turnout rates like Belgium and Turkey.