What action should be taken to change the alignment of objects on a slide in PowerPoint?

To change the alignment of objects on a slide in PowerPoint, using the Format ribbon's Align button is the correct approach. The Format ribbon provides specific tools tailored to formatting selected objects, including alignment options that allow you to align shapes, text boxes, and images relative to each other or the slide itself. By clicking the Align button, you can vertically or horizontally align selected objects to achieve a balanced and organized layout, ensuring that your design is visually appealing and communicates your information effectively.

The other methods mentioned might not directly cater to alignment tasks. For instance, the Insert tab focuses more on adding new elements to the slide rather than formatting existing ones. The Home tab is primarily for text formatting and basic object manipulation, but it doesn't provide the comprehensive alignment tools found on the Format ribbon. Meanwhile, the Design tab is typically used for overall slide design and themes rather than positioning individual objects. Therefore, the Align option within the Format ribbon is the most effective and direct method for adjusting alignment.