In the late 1800s, which country faced the greatest challenge remaining unified with a large variety of ethnic groups seeking independence within its borders?

Austria-Hungary was a multinational empire containing many ethnic groups, including Czechs, Slovaks, Croats, Serbs, and others. Many sought greater autonomy or independence, making it especially difficult to keep the empire unified. France, Germany, and Britain also had internal differences, but Austria-Hungary faced the most intense challenge from competing national movements.

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