What surprised the british at bunker hill ? a) how disciplined the soldiers were firing at the british troops b) how well supplied the colonist were c) how the colonists could hold the hill d) how fast the conlonist created an embankment

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 enslaved people onboard suffered from illness with some frequency