Answer:
They are sometimes factual
Explanation:
The truism about details of setting and plot in historical fiction is that they are factual sometimes.
A historical fiction is a type of writing where the story line happens in the past. One major characteristic is that it is sometimes factual and other times is inaccurate.
Most slaves lived on plantations, but the plantations were not very big: they rarely had more than 100 slaves. The best answer is then A. lived on plantations with 20 or more slaves.
C. Female children in Sparta were sequestered (hidden indoors)
(My answer depends on what textbook you are reading or were your text is to support it)