What problems did germany face at the end of the 20th century?

Top among the problems that Germany faced was economic stagnation. Germany experienced a stagnant economy by the 1980s. Reunification of East and West Germany exacerbated the problem because East Germany's formerly communist economy was very depressed and in need of reform.

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: