Final answer:
The beginning of a historical narrative should always include the reason for writing, as it sets the context and purpose for the narrative.
Step-by-step explanation:
At the beginning of a historical narrative, it is important to set the stage for the reader. The inclusion that is always necessary at the beginning of a historical narrative is the reason you are writing (A). This introduction sets the context for the narrative and helps the reader understand the significance of the events that will be described. A historical narrative should capture the reader's interest by presenting the purpose of the narrative, which may be to inform, to explain the significance of an event, or to explore the development of an individual.
While personal feelings (B) and what you saw during an event (D) can be included, they are not always mandatory. Incorporating details about your life at the time (C) can provide valuable context but is not an essential starting point unless it directly relates to the event being discussed.