Meh, my heart says #1, but I'm pretty sure 3 is the correct way to play with the rules as written.
I've got my fingers crossed that a
GW FAQ changes that, but until then you don't get an
EL roll for units that were taken out by a Sweeping Advance.
Still, this is definitely a case of something that is going to be a "House Rule" until there's official clarification, so start lobbying your
LGS/Tournament Organizers now.