In this section, you choose which countries and territories you have the rights to publish in. There are two radio buttons that you can select (and you can select only one), and they look like this:
One button indicates that you have worldwide publishing rights and that you want to make the book available in all countries and territories. The other button lets you choose individual countries and territories from a list of 245.
Unless you have reasons not to publish in a territory, I would choose the option for publishing worldwide. And if you’re publishing a public domain work, you need to be aware of the following (which you’ll see if you hover your cursor over the “(What’s this?)” link):
If you are publishing a public domain title, keep in mind that the duration of copyright varies between countries, so ensure you set your territory rights to only include those territories where you have determined the book is in the public domain.