The correct answer is: It can be proven using objective evidence.
To be<em> factual</em> is to use or consist of facts, meaning the information provided can be proven and its characteristics are not altered by external interpretations (opinions from others).
Just as facts, <em>objective evidence</em> can be proven by observation and analysis. Regarding the excerpt, it can be proven that Hossack was struck at the head by analyzing his corpse, and that the crime took place "a few miles out from Bedford" by visiting the crime scene.
Your answer will be the last option:
Using sensory details to describe and create an image for readers.
This is exactly what imagery portrays in any type of art, not memoir alone.
You can say something like
" well, there were many similarities within the book and the movie. there were also many notable differences as well. the story had many more details that the movie left out."
