Title: Provinces of Bulgaria
Content:  The provinces of Bulgaria (области на България) are the first-level administrative subdivisions of the country. Since 1999, Bulgaria has been divided into 28 provinces (области – oblasti; singular: област – oblast; also translated as "regions") which correspond approximately to the 28 districts (in окръг – okrǎg, plural: окръзи – okrǎzi), that existed before 1987. The provinces are further subdivided into 265 municipalities (singular: община – obshtina, plural: общини – obshtini). Sofia – the capital city of Bulgaria and the largest settlement in the country – is the administrative centre of both Sofia Province and Sofia City Province (Sofia-grad). The capital is included (together with three other cities plus 34 villages) in Sofia Capital Municipality (over 90% of whose population lives in Sofia), which is the sole municipality comprising Sofia City province.
Title: Bulgaria
Content:  Bulgaria (България), officially the Republic of Bulgaria, is a country in Southeast Europe. It lies on the eastern flank of the Balkans, and is bordered by Romania to the north, Serbia and North Macedonia to the west, Greece and Turkey to the south, and the Black Sea to the east. Bulgaria covers a territory of 110994 km2, and is the sixteenth-largest country in Europe. Sofia is the nation's capital and largest city; other major cities are Plovdiv, Varna and Burgas. One of the earliest societies in the lands of modern-day Bulgaria was the Neolithic Karanovo culture, which dates back to 6,500 BC. In the 6th to 3rd century BC the region was a battleground for ancient Thracians, Persians, Celts and Macedonians; stability came when 
Title: Sofia
Content:  Sofia ( София, ) is the capital and largest city of Bulgaria. It is situated in the Sofia Valley at the foot of the Vitosha mountain in the western parts of the country. The city is built west of the Iskar river, and has many mineral springs, such as the Sofia Central Mineral Baths. It has a humid continental climate. Being in the centre of the Balkans, it is midway between the Black Sea and the Adriatic Sea, and closest to the Aegean Sea. Known as Serdica in Antiquity and Sredets in the Middle Ages, Sofia has been an area of human habitation since at 
Title: Sofia
Content:  regional capital of Rumelia Eyalet, the Ottoman Empire's key province in Europe. Bulgarian rule was restored in 1878. Sofia was selected as the capital of the Third Bulgarian State in the next year, ushering a period of intense demographic and economic growth. Sofia is the 14th largest city in the European Union. It is surrounded by mountainsides, such as Vitosha by the southern side, Lyulin by the western side, and the Balkan Mountains by the north, which makes it the third highest European capital after Andorra la Vella and Madrid. Being Bulgaria's primate city, Sofia is home of many of the major local universities, cultural 
Title: Plovdiv
Content:  Plovdiv (Пловдив, ) is the second-largest city in Bulgaria, standing on the banks of the Maritsa river in the historical region of Thrace. It has a population of 346,893 and 675,000 in the greater metropolitan area. Plovdiv is the cultural capital of Bulgaria and was the European Capital of Culture in 2019. It is an important economic, transport, cultural, and educational center. During most of its recorded history, Plovdiv was known by the name Philippopolis after Philip II of Macedon. Plovdiv is situated in a fertile region of south-central Bulgaria on the two banks of the Maritsa River. The city has 
Title: Outline of Bulgaria
Content: Capital of Bulgaria: Sofia ; Cities and towns of Bulgaria ; Villages of Bulgaria Municipalities of Bulgaria
Title: Burgas
Content:  Burgas (Бургас, ), sometimes transliterated as Bourgas, is the second largest city on the Bulgarian Black Sea Coast in the region of Northern Thrace and the fourth-largest in Bulgaria after Sofia, Plovdiv, and Varna, with a population of 202,694 inhabitants, while 277,922 live in its urban area. It is the capital of Burgas Province and an important industrial, transport, cultural and tourist centre. The city is surrounded by the Burgas Lakes and located at the westernmost point of the Black Sea, at the large Burgas Bay. The LUKOIL Neftochim Burgas is the largest oil refinery in southeastern Europe and the largest industrial enterprise. The Port of Burgas is the largest port in Bulgaria, and Burgas Airport is the second most important in the country. Burgas is the centre of the Bulgarian fishing and fish processing industry.
Title: Outline of Bulgaria
Content: Form of government: parliamentary republic ; Capital of Bulgaria: Sofia ; Elections in Bulgaria ; Political parties in Bulgaria Politics of Bulgaria
Title: Roman Catholic Diocese of Sofia and Plovdiv
Content:  of the population was Paulician or Manichaean, heresies from both Catholic and (later) Orthodox points of view. After some years of troubles it again fell into the power of the Bulgars. Its present name of Sophia dates from the Middle Ages, though the precise date of its first use cannot be assigned; in the sixteenth century Sredetz and Sophia were used simultaneously. In 1382 the city was captured by the Ottoman Turks, and for more than four centuries it was the residence of the beglerbeg (governor general) of all Rumelia. In 1878 Sophia was chosen as the capital of the tributary Principality of Bulgaria, and since 1908 became the capital of the Kingdom of Bulgaria, later of the present republic.
Title: Plovdiv
Content:  According to the Treaty of San Stefano on 3 March 1878, the Principality of Bulgaria included the lands with predominantly Bulgarian population. Plovdiv which was the biggest and most vibrant Bulgarian city was selected as a capital of the restored country and for a seat of the Temporary Russian Government. Great Britain and Austria-Hungary, however, did not approve that treaty and the final result of the war was concluded in the Congress of Berlin which divided the newly liberated country into several parts. It separated the autonomous region of Eastern Rumelia from Bulgaria, and Plovdiv became its capital. The Ottoman Empire created a constitution and appointed a governor. In the spring of 1885, Zahari Stoyanov formed the Secret 

Question: What is the capital of Kingdom of Bulgaria?
Answer: Sofia.
Serdica.
Sredez.
Sofija.
Sredets.