Step 1: Understanding the concept.
The question refers to presentation software (like PowerPoint), where content is divided into separate sections or pages to organize information effectively.
Step 2: Analyzing the options.
• (A) Text: Text is content written on a page, not the page itself.
• (B) Document: A document is a complete file, not individual pages within a presentation.
• (C) File: A file is the entire saved presentation, not its parts.
• (D) Slides: Correct. Slides are individual pages in a presentation used to separate and present different topics.
Step 3: Conclusion.
Thus, in a presentation, different topics are separated using slides.
Final Answer: Slides.