The correct answer is the following: <em>option a. The universal theme of a story is often revealed at the resolution of the story, when the reader can see how the story ends.</em>
In literature the terms of "theme" and "universal theme" are commonly used. While the theme of a work of literature is defined as the main message revealed through a story, the universal theme is defined as a theme that applies to anyone and everywhere, that is relatable to a wide set of readers.
In both cases, to know the theme or the universal theme of a piece of literature work, it is needed to read through the whole story and analyze it to find out what the theme of it is, and if it can be a universal theme relatable to a big audience.