Kathy this is a very disappointing and not uncommon reply from Microsoft. It is less than 2 months old and it does not reflect the actual options available when one follows your instructions explicitly. There is no such place to make such a selection just as reported by the person who asked the original question.
This will soon be a HUGE issue as I am (and naturally I am not the only one) getting inundated with spam meeting invitations from advertisers that appear on my calendar making hundreds of entries.
Microsoft needs to address this asap; please advise as soon as this is fixed.