This is wrong.
As a subject, “either” is singular. it’s the opposite of “both,” and refers to one at a time: “Either ketchup or mustard is good on a hot dog.” But if “either” is modifying a subject in an “either . . . or” phrase, then the number of the verb is determined by the number of the second noun: “Either the puppy or the twins seem to need my attention every other minute.”
as stated on Washington State University web page.
I think we’re agreeing that in this sentence, the correct answer is b.
I do appreciate your pointing out that if we had said “either / or”, the noun closes to the verb would determine agreement. Thanks for giving us a great future question!
Nope Icepir8 is right. Take the EITHER out of the sentence. Since either is still single you need to say Are. You wouldn’t say “Is you available to meet with the Cisco rep tomorrow?” You say “are you”. Therefore, when addressing 2 or more people “singlularly” with the same sentence, single words apply.
I can’t take “either” out of the sentence. It’s the subject.
The pronouns neither and either are singular when used as the subject of the sentence and require singular verbs. Substitute “either” for some other singular pronoun — she, for instance.
Is she available to meet with the Cisco rep tomorrow?
(You wouldn’t say “Are she available to meet…”)
You are still incorrect. You are correct the the subject of the sentence is singular. It is “you”. The correct conjugation for “to be” in the second person singular is “are”, as in “Are you available to meet with Cisco…”. “Is” is the correct in the statement, “Is she available to meet..” , because “is” the correct conjugation of “to be” for 3rd person singular. Thus the correct responses would be: “Are either of you available to meet..” and “Is he or she available to meet…”.