Advanced Controls For Dropdowns in Form Designer

Trying to get some dynamic dropdowns working and was hoping someone has gotten this working.

Assign Activity = CountryList = new List(of string)(new string(){“one”,“two”,“three”})
Type = System.Collections.Generic.List<System.String>

Reference: Advanced Controls in the Form Designer (uipath.com)

(Collection)[…]
Form Data Has
CountryList_dropdown In List CountryList
CountryList Out String Enter a VB expression

The _dropdown is theoretically going to populate my select list.
While it does appear, there are no options visible. The Package is available here to look at. Any insight on why the options are not visible?

FormTasks (2).zip (3.1 KB)