A family of Microsoft word processing software products for creating web, email, and print documents.
I found my own answer:
Click the list arrow to the right of the QAT, enable Automatically Save. From the QAT, set AutoSave to Off. When you exit Word, you will now be prompted to save changes. I also went back to Word Options to enable background saves. I also note that on some documents, AutoSave is dimmed on the QAT. And when I open some documents, AutoSave is still enabled, so evidently, adjusting the QAT in one document does not affect this feature in the QAT in other documents. Going forward, I'm just going to have to be very aware of this setting on the QAT and adjust the On/Off setting accordingly.
Forum moderators need to help us by doing more research before posting incorrect advice.
Note that in a new document, on the QAT, AutoSave, Off, is dimmed.