The correct answer is D. Bulgaria rebelled against the Ottomans and established an independent state.
Step-by-step explanation
In the XIV century after three months of attacks, the Ottomans finally took control in the capital city of the Second Bulgarian Empire, this situation caused the oppression, inequality, and exploitation from ottomans to the Bulgarian population because they had to pay more expensive taxes and the justice was not equal for them. The Ottomans dominion lasted around five centuries until the Bulgarian people started to revolt without favorable results. However, the situation caused international impact that drew attention from other nations including Russia, that faced the Ottomans and defeated them giving freedom to Bulgaria which would be declared as a principality and finally in 1908 as an} Independent state. So, the correct answer is D. Bulgaria.