Teacher:In this task, you're given a question, a context passage, and four options which are terms from the passage. After reading a passage, you will get a brief understanding of the terms. Your job is to determine by searching and reading further information of which term you can answer the question. Indicate your choice as 'a', 'b', 'c', or 'd'. If you think more than one option is plausible, choose the more probable option to help you answer the question.
Teacher: Now, understand the problem? Solve this instance: Question: What was the combined population of Bessarabia and Wallachian Plain during the formation of Bulgaria? Passage:The Byzantine Empire held the region between the Danube and the Black Sea (modern Dobruja) from time to time (such as during Justinian's reign in the 6th century) or again under some emperors of the Macedonian and Komnenian dynasties, being part of the Byzantine Paristrion thema (province) between in the period 971976 and between 1001 and 1185, although it was a border that was hard to maintain due to the constant invasions from the north. Dobrudja was part of the Bulgarian Empire during its whole period of existence. The area around the Danube Delta was the site of battle of Ongal in 680 which led to the formation of Bulgaria in 681. Since the formation of the country the Bulgarians controlled the Wallachian Plain and Bessarabia to the north of the Danube, bordering the Avars to the north-west. The Bulgarians under Khan Krum destroyed the crumbling Avar Khanate in 803 and moved the border along the river Tisza, thus including Transylvania and parts of Pannonia in the Bulgarian state. In a military conflict with the Franks between 827829 the Bulgarians secured their border with the Frankish Empire.
Links: a. Bessarabia b. Danube Delta c. Byzantine Empire d. Bessarabia
Student:
a