I set up a survey, posted and shared it. Potential users see this screen when they go to the web site.

I find it very suspicious that in Survey123 the "Members of my organization" box is grayed out.

1) Maybe it doesn't matter,
2) maybe my account is not set up to allow me to share things publicly, or
3) maybe Survey123 is designed so that anyone can contribute, but only if they have an ArcGIS account.
Which is it?