Heh... although it certainly does return a single integer (which is the answer I chose based on a coin flip between A and C), answer C is actually much more correct. While an integer is certainly returned, that integer is a single element result set that identifies all of the SET options currently enabled for me as a user. Just because it needs a little more work to figure out what the integer represents doesn't actually diminish the fact that it's a result set of 1 element that contains information as to all of the SET options that I have On or Off.
And the explanation of the answer is technically incorrect, as well. It states...
@@OPTIONS returns a binary value that represents a bitmap of your SET options
It patently is NOT a binary value. It IS an integer value that represents a bitmap. 😉
Still, great question. I've never used @@OPTION before.