How to reset Drop Down control value (NOT uidropdown) - with example

I have the following code (showing picture because I can't display the drop down here)

I can't find a way to make sure that each time the code is run, the drop down is set to the first item in the list. The second line was my attempt but it doesn't work. Is there a way to do this (in the Configure Control dialog the default is set to "Acetamide". Sample code is attached.