Answer:
In a work of fiction, the best place to look for supporting details that indicate the theme is in the dialogues and descriptions.
Step-by-step explanation:
Dialogs and descriptions are two major elements in fiction writing, along with the narrative. The whole theme - the story itself - will be developed through those elements.
Dialogs are the conversational interactions between characters. The plot may be advanced through such interactions, and some part of the characters' personalities may be revealed. A description is a device used by the author to give readers the information they need to better sense and visualize the characters, the setting, the mood etc. The details offered in a description will allow readers to picture the place, to know the characters' physical appearance and personality traits, to feel emotions, and even imagine sensory sensations such as cold weather or tasty food.