3. ________ A character who undergoes significant development throughout the course of a story.

The term you are looking for is "dynamic character." A dynamic character is one who experiences significant internal change throughout the narrative, often as a result of various events, conflicts, and interactions with other characters. This evolution can manifest in their attitudes, beliefs, or relationships, making them a crucial element of storytelling.

Dynamic characters are often contrasted with static characters, who remain largely unchanged from the beginning to the end of the story. For example, in literature, a protagonist may start off with a specific worldview or set of beliefs that are challenged by the events they encounter, leading to growth and transformation. This character arc enhances emotional engagement for readers, as they witness the struggles and triumphs of the character, making the story more compelling. Dynamic characters serve to illustrate themes and messages within the narrative effectively.