Should I use "is" or "are" in this sentence?

The next canonical choice [is/are] the so-called slip boundary conditions...

I've struggled to find an answer for this question elsewhere.

I think that "is" is correct here, since the object of the sentence, the "canonical choice", is singular, thus we use the singlular form, "is". However, it doesn't quite sound right when combined with the plural "boundary conditions". Should the form of "is" (singular or plural) depend on the "choice" or the "conditions"?

N.B. If there is a name for this kind of sentence or for parts of this kind of sentence, I'd be grateful if someone could tell me (so that it is easier to find information about them in future).

  • In English, tensed verbs only ever agree with that verb's subject alone, never with any of its objects or other complements. I don't know of any other languages where some different rule than this one applies, either.
    – tchrist
    Commented Jul 30, 2022 at 15:54
  • Maybe it sounds odd because it should be should be "choices ... are ... conditions". Commented Jul 31, 2022 at 0:40