Final answer:
In Microsoft Project, the Multiple Level Undo function is used to reverse actions you have performed. This allows you to go back through multiple steps, fixing mistakes or reviewing changes.
Step-by-step explanation:
The function that allows you to reverse actions you have performed in Microsoft Project is the Multiple Level Undo. This feature is incredibly helpful when you need to correct mistakes or simply reconsider the steps you have taken during your project planning process. Unlike a single undo, the Multiple Level Undo function lets you undo several actions in the order they were made.