The purpose of Slide Show tab in PowerPoint is:

Microsoft PowerPoint is a powerful tool for creating and delivering presentations, organized into various tabs for different functionalities.

• The Slide Show tab's primary purpose is to preview and control the slide show. This tab contains options to start the presentation from the beginning or current slide, set up the slide show (e.g., loop, timings), hide slides, and record narration. It focuses on the delivery and viewing experience of the presentation.
• Insert images and videos (A) is primarily handled by the 'Insert' tab.
• Change design & layout (C) is mainly managed through the 'Design' tab for themes and backgrounds, and the 'Home' tab for slide layouts.
• Create animations (D) is the function of the 'Animations' tab, where you can apply motion effects to objects on your slides.

Each tab in PowerPoint serves a distinct organizational purpose, making the 'Slide Show' tab essential for presentation delivery.