Answer:
D.
Step-by-step explanation:
By process of elimination, this passage is not arguing about the topics of a specific event, it's broadly warning readers that Historians tend to make bias arguments based on their background or knowledge of an event. The author was only providing an example, but that doesn't mean it's what the whole paragraph is aout. It's also not remotely saying Bias needs to be removed, it's just saying it exists.
Hopefully this helps! :D