Final answer:
Consulting the contest guidelines is crucial, but a diary format can be used for writing historical fiction if permitted by the rules. This style allows a personal reflection of events and historical details.
Step-by-step explanation:
Option d) consult the contest guidelines is the most prudent advice for understanding what format is acceptable in the Daughters of the American Revolution essay contest. However, traditionally, historical fiction can indeed be written in the form of diary entries.
This approach allows for personal reflections and descriptions of events, and can be an effective way to tell a story with historical details without relying heavily on dialogue. The diary format is a form of primary source, which could breathe authenticity into your historical narrative. When structuring your essay, consider focusing on a specific moment in time or series of events and adopt a style that best serves your narrative, while staying within the guidelines provided by the contest.