Showing only the layers stack won't help us.
EDIT
Please next time do a full screenshot of GIMP. It will allow us to not spend time to "decipher" what you're trying to show us as it took me a while to understand that what's you wanted to show us is just a bit of the bottom of the Brushes dialog above the layer,s stack and this has nothing to do with Tool Options...
Try in the top menu Windows ➤ Dockable Dialogs ➤ Tool Options, it should appear if not open, or highlight for a second if the tab is already opened.
EDIT
Please next time do a full screenshot of GIMP. It will allow us to not spend time to "decipher" what you're trying to show us as it took me a while to understand that what's you wanted to show us is just a bit of the bottom of the Brushes dialog above the layer,s stack and this has nothing to do with Tool Options...
Try in the top menu Windows ➤ Dockable Dialogs ➤ Tool Options, it should appear if not open, or highlight for a second if the tab is already opened.