Why did east germans emigrate to west germany/west berlin?

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:

the first action that caused many creek indians to turn against william mcintosh was when mcintosh a) supported the united states during the creek war of 1813–1814. b) attempted to stop the sale of creek land to the u.s. government. c) seized control of over 1,000 acres of land belonging to the creeks.