What should be used to highlight or emphasize text in APA format?

In APA format, italics are used primarily to signify titles of longer works, such as books, reports, or films, and to emphasize specific words or phrases when necessary. This is the preferred method of emphasis in academic writing, as it maintains a level of professionalism and readability that aligns with APA style guidelines. While bold text can be effective for headings and underlining can occasionally be used in specific contexts, neither is considered standard for emphasizing text in APA formatting. Therefore, relying on italics for emphasis adheres directly to APA's stylistic norms, making it the correct choice.