none of the above

Send an e-mail to the person who made the mistake of sending it to you, and tell him that "I think my name is listed as recipient by accident".  No need to say more.  Don't send to anybody else.  He will be able to make the correction within the group.

Only if you want to take this opportunity to impress the higher-ups, for which I don't have any good suggestion on that.  But, it backfires easily.