Final answer:
Sentence 4, which asks readers to ponder the true value of refusing to change, is the sentence that most clearly provides a closing thought in the conclusion paragraph.
Step-by-step explanation:
The sentence in the conclusion paragraph that most clearly leaves the reader with a closing thought is sentence 4: "Ultimately, readers are left to wonder about the true value of refusing to change." This statement invites readers to reflect on the central theme of the tragedy and ponder its relevance to their own lives and beliefs. It directly addresses the consequences of the characters' actions and poses a poignant question that resonates beyond the context of the play, making it an effective concluding thought.