Atheme is best described as —
a. a moral lesson presented in a work of literature
b. the central idea or insight about life revealed in a literary work
c. the subject of a work of literature
d. a series of related events in a literary work

The correct answer is B. The central idea or insight about life revealed in a literary work.

This central idea however has nothing to do with the actual stuff happening in the book, it is just an underlying idea that can be applied to many different art forms, or explored in numerous pieces of art.