Which option is NOT available through the "Transitions" tab?

The "Transitions" tab in PowerPoint is specifically designed for managing the visual transitions that occur when switching from one slide to the next. This includes features such as selecting different transition effects, adjusting the duration of those transitions, and setting up automatic transitions to advance slides after a specified time. All of these functionalities enhance the flow of the presentation.

Changing text formatting, however, is not a feature found in the "Transitions" tab. Text formatting adjustments—such as altering font size, style, or color—are typically managed through the "Home" tab. Therefore, this option does not align with the purpose of the "Transitions" tab and is why it is the correct answer to this question.