Triple

Given a phrase, classify it is english named entity (e.g., persons, organizations, works of art) in Latin script, or not (e.g., literals, dates, URLs, verbose phrases). For disambiguation, the statement where the phrase occurs as object is also given. Please return a JSON object with `phrase` (string, the phrase being analyzed) and `is_ne` (boolean, indicating whether the phrase is a Named Entity).

Phrase: Bulgarian tsars | Statement: [perpera, issuer, Bulgarian tsars]

Target entity: Bulgarian tsars
Context triple: [perpera, issuer, Bulgarian tsars]

• A. Presian I of Bulgaria
  Presian I of Bulgaria was a 9th-century khan who significantly expanded the First Bulgarian Empire into the Balkans prior to the Christianization under his successor Boris I.
• B. Peter I of Bulgaria
  Peter I of Bulgaria was a 10th-century tsar of the First Bulgarian Empire known for his long and relatively peaceful reign, during which Bulgaria strengthened its Christianity and diplomatic ties with Byzantium.
• C. Boris II of Bulgaria
  Boris II of Bulgaria was a 10th-century Bulgarian tsar whose short and troubled reign marked the beginning of the decline of the First Bulgarian Empire under Byzantine pressure.
• D. Peter IV of Bulgaria
  Peter IV of Bulgaria was a medieval Bulgarian tsar who played a key role in the restoration of Bulgarian independence and the establishment of the Second Bulgarian Empire in the late 12th century.
• E. Alexander I of Bulgaria
  Alexander I of Bulgaria was the first modern ruler of an autonomous Bulgaria after Ottoman rule, reigning as prince from 1879 to 1886 during the formative years of the Bulgarian state.
• F. None of above. chosen
• G. Unsure - the case is ambiguous/there is not enough information to decide.

Generate a one-sentence description of the target entity. 
You are given a context triple in the form (subject, predicate, object), where the object is the target entity. 
# Instructions
Use the triple to infer relevant information about the entity. Describe the entity based on what is most defining, well-known. 
Avoid repeating the information from the triple, unless really essential.
# Response Format
Return only the sentence: "Description: [one-sentence description of the target entity]"

Entity: Bulgarian tsars
Triple: [perpera, issuer, Bulgarian tsars]

Bulgarian tsars were the medieval monarchs who ruled the Bulgarian Empire, overseeing its political, military, and cultural life during its periods of regional power in Southeast Europe.

Target entity: Bulgarian tsars
Target entity description: Bulgarian tsars were the medieval monarchs who ruled the Bulgarian Empire, overseeing its political, military, and cultural life during its periods of regional power in Southeast Europe.

• A. Presian I of Bulgaria
  Presian I of Bulgaria was a 9th-century khan who significantly expanded the First Bulgarian Empire into the Balkans prior to the Christianization under his successor Boris I.
• B. Peter I of Bulgaria
  Peter I of Bulgaria was a 10th-century tsar of the First Bulgarian Empire known for his long and relatively peaceful reign, during which Bulgaria strengthened its Christianity and diplomatic ties with Byzantium.
• C. Boris II of Bulgaria
  Boris II of Bulgaria was a 10th-century Bulgarian tsar whose short and troubled reign marked the beginning of the decline of the First Bulgarian Empire under Byzantine pressure.
• D. Peter IV of Bulgaria
  Peter IV of Bulgaria was a medieval Bulgarian tsar who played a key role in the restoration of Bulgarian independence and the establishment of the Second Bulgarian Empire in the late 12th century.
• E. Alexander I of Bulgaria
  Alexander I of Bulgaria was the first modern ruler of an autonomous Bulgaria after Ottoman rule, reigning as prince from 1879 to 1886 during the formative years of the Bulgarian state.
• F. None of above. chosen