What is a critical requirement for slide titles in PowerPoint presentations?

Every slide must have a unique title if different content is displayed because unique slide titles aid in navigation and understanding of the presentation's structure. Search engines, screen readers, and other assistive technologies rely on clear and distinct titles to help users comprehend the content of each slide.

Using unique titles helps users with disabilities, particularly those who rely on screen readers, to effectively navigate through the slides. When each slide has a specific title that represents its content, it enhances accessibility by providing context and improving the user's overall experience. This practice not only complies with accessibility guidelines but also supports clear communication and organization of ideas within the presentation.

The other choices do not align with best practices for accessibility. For instance, using the same title across all slides would lead to confusion and a lack of clarity about the distinct information presented on each slide. Title case or decorative titles, while stylistically appealing, may detract from functionality and can make it difficult for screen readers to interpret the information accurately.