Answer:
a.) inability of authors to know every cause and consequence of every story.
Step-by-step explanation:
Historians are concerned with accuracy in their writings. In general, all authors want their work to reflect reality as correctly as possible. However, authors are also aware of their inability to know every cause and consequence of every story. Their inability to be informed of every detail of a story means that they might miss some event that was significant to the time period they are studying.