@subsguts
Another option (because If statements in Items properties are not good practice) would be to specify your data in your primary dropdown.
So, the Items property for Dropdown A as:
Table(
{Value: "Yes", Values: ["Complete", "In Progress", "Not Started", "N/A", "Need Info"]},
{Value: "No", Values: ["N/A"]}
)
Then, the Items property for Dropdown B set to:
DropdownA.Selected.Values
No If's or Defaults needed, it would simply have the correct options based on the choice.