Which of the following refers to jewelry used by actors in a performance?

The term "costume accessories" refers specifically to additional items, like jewelry, that actors wear to enhance their costumes during a performance. Accessories enrich the visual representation of characters, contributing to the overall authenticity and depth of the portrayal. Jewelry, as an example of costume accessories, can indicate aspects of a character's identity, status, or cultural background.

Other selections, while they may seem related, do not specifically encompass the context of jewelry. For instance, "costume embellishments" generally refer to decorative elements sewn or attached onto a costume itself rather than items worn. "Character artifacts" might imply objects that have meaning or relevance to a character's storyline or history, but do not clearly denote jewelry or accessories worn as part of a costume. "Costume enhancements" broadly suggests improvements to the overall look but lacks the specificity to refer solely to items like jewelry that are integral to a performance. Therefore, "costume accessories" is the most precise term that aligns with jewelry used by actors.