Yes. Complete the first 10 and save the choice. Go back and update the Choice and you will see you have more choices. You may have to do this multiple times if you have large numbers of options.
There is no programmatic limit, but there are practical limits. Very deeply nested structures are difficult to manage. 3 levels of categories should be sufficient for most situations.
Note that there is always at least one level of categories, since the Course category always encompasses all other categories and grade items, can cannot be deleted.