Sentence Correction (SC) | Re: As of this morning, none of my friends have been able to

The issue seems to be none - is it plural or singular?
In colloquial English I have often heard 'none of my friends had been able to catch the morning train' - but here D (OA) says 'is' singular is applicable?
So, does 'none' apply to singular bunches of entities? (family, team/ board of director(S) and so on)
on the GMAT if such a question comes what do we pick?

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