Eyewitnesses often have different accounts of events, so historians must

Evaluate each account to discover the truth is the correct answer. As there is a possibility of different events recorded by different eyewitnesses but who to believe is the question.

So the historians must evaluate and analyse all the records in such a manner that the eyewitness's account is matched with the other evidences. There should be careful evaluation of all the records to avoid errors and wrong interpretation of the given facts.