Which shortcuts can you use for Undo and Redo?

Select an answer:

Ctrl$+$Z for Undo and Ctrl$+$Y for Redo

Alt$+$U for Undo and Alt$+$R for Redo

Ctrl$+$U for Undo and Ctrl$+$R for Redo

Ctrl$+$Y for Undo and Ctrl$+$Z for Redo