Answer: evaluate each account to discover the truth.
Historians are often faced with a dilemma when studying events of the past. It is difficult for them to reconcile contrasting accounts or to establish which account is more likely to be right. Therefore, they must evaluate each account carefully. Historians, however, rely on different strategies in order to get closer to the truth. For example, they might study how an event fits in with the events that occured immediately before or after it. They might also study how different time periods have analyzed specific past events. Finally, they might ask whether the witness was under pressure to provide a particular account. All of these strategies help us get more accurate information regarding historical events.
D, because the enlightenment was about science and the relationship between rulers and subjects is not going to be able to be solved by science. Hope it helps!