Voboy
Sometime Wordwright
- Joined
- Mar 21, 2016
- Posts
- 6,044
Multiple possible answers. I'm happy with 'are'.
Not at all.
You don't modify a singular noun with a plural verb. "Which of" is a contraction for "which one of," and there's no noun more singular than "one."
Don't take it personally. I only do this sort of thing on threads that are asking about grammar. I enjoy the irony.
As for your actual question, it arises periodically on the AH. The consensus seems to be, as you'd put it, that there are "multiple possible answers." Though I'd side with 2 and 4, myself.