Fewer multiparty countries than single-party countries have weak local governments. The majority of countries with weak local governments have a single political party. Some countries with weak local governments have a plurality of political parties. Some countries with weak local governments do not have corrupt national governments.
Political theorist: The vast majority of countries that have a single political party have corrupt national governments, but some countries with a plurality of parties also have corrupt national governments. What all countries with corrupt national governments have in common, however, is the weakness of local governments.
If all of the political theorist's statements are true, which one of the following must also be true?