I am embarassed to admit that I got this question, that apparently was based on my comments, wrong.
I should have been warned. I even checked the code several times. All because I thought that if both programs run without error (as I assumed), there would have been THREE correct answers. So I checked. And checked again.
I did contemplate the extra comma, but figured that this would not be Ron's style, so it had to be a genuine type (hint: test all code before submitting QotD!)
I did also contemplate the inconsistent use of upper- and lowercase, but figure that wouldn't be Ron's style either (hint: test all code on a database with case-sensitive collation)
And after reading the script yet another time, I ticked the first three options - and then kicked myself for overlooking the named constraint.
Thanks, Ron! Good question (though unfortunately hampered by the typo and the inconsistent upper-/lowercase).