How was the catholic church a unifying force in the middle east europe

Explanation:

During the middle ages, the church was a unifying force. it shaped people's beliefs and guided their conduct. most europeans at this time shared a common bond of faith, during the middle ages, two powerful leaders were Charlemagne and Otto the great- tried to revive the idea of empire.

plz mark as brainliest

option d is correct. corroborated sources of historical evidence   is necessary to validate a claim about an event in history.

historians tend to use written sources, but audio and visual materials as well as artifacts are important objects that supply information to modern historians.

historical sources are usually divided into two categories: primary and secondary sources. depending on the historian's intent, some sources shift their designation. determining what type of sources toimplement, and the level of credibility and reliability of those sources, is a significant step in critical thinking for the historian.

explanation:

they were byzantines