Question about setting the value in Drop Down

I have what I think is a simple question but can't seem to find an answer. I have almost everything working as I am using the inline editor, specifically a dropdown field. I am populating the dropdown successfully, but don't know how to select its value after it is populated to match what's in the database.

The dropdown is set up thusly.
{
name: "supplier",
type: "select",
options: retrieveDropdownData() // gets the list formatted appropriately
}
I need each row to have its select values set correctly before allowing the user to change the fields. Thanks for any insight.

-Gabe