What element of storytelling often highlights a character's inner thoughts?

The element of storytelling that often highlights a character's inner thoughts is narration. Narration provides the voice that tells the story and can delve into the thoughts, feelings, and motivations of characters. Through narration, readers gain insight into a character's internal struggles, fears, and desires, allowing for a deeper understanding of their actions and decisions within the story.

In contrast, options like diatribe focus more on critical commentary or lengthy and aggressive speech, which doesn't typically convey a character's internal dialogue. Dialogue represents spoken exchanges between characters, which can reveal relationships and conflicts but does not inherently express a character's thoughts. Exposition provides necessary background information and context for the story but is not primarily concerned with revealing a character's inner thoughts. Hence, narration stands out as the best choice for highlighting a character's internal perspective.