Final answer:
Balkan nationalism played a key role in the decline of the Ottoman Empire by causing regional instability as various ethnic groups sought independence, resulting in weakened Ottoman control and increased European intervention. The correct option is c.
Step-by-step explanation:
Balkan nationalism significantly contributed to the decline of the Ottoman Empire primarily by causing instability in the region. As nationalism grew within various ethnic groups in the Balkans, these groups started to seek autonomy and independence, which challenged Ottoman authority.
For example, the Greeks fought for and won their independence in the early 19th century, and other nations like Serbia, Romania, and Bulgaria followed in the latter part of the century.
The rise of nationalism in the Balkans led to the Ottoman Empire being unable to maintain its control over these territories, as each nationality sought to create its own state.
Moreover, Balkan conflicts and wars contributed to the weakening of the empire, as other European nations took advantage of the declining Ottoman power to increase their influence in the region. This scramble by European powers like Austria-Hungary to occupy parts of the Balkans further destabilized the Ottoman grip on the territory.
Additionally, the Ottoman Empire faced other problems that contributed to its decline, including financial troubles, increasing debt, and warfare on its eastern front. Nationalism within the empire's many ethnic groups exacerbated these issues, making governance increasingly difficult and leading to further loss of territory and power. The correct option is c.