1. What were three factors leading to war? 2. What two groups of nations developed? 3. How were the Serbians involved in the start of World War I?

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:

hello! : )

i think a judge or jury, as they preside over the court and is the central figure in a trial.

hope this and i hope i answered in time!

good luck!

~ destiny ^_^