I don't think it matters (other than "not C"), but I'm very slightly inclined toward A. The joists (yes, they should run parallel to the 4' sides, not the 8' sides) are going to be nailed in from the sides, so if you do A your end pieces will be nailed in from the top and bottom edges (as laid out here). That seems better than doing everything in the same direction, for reasons I can't really justify.
You might ping Filip of the Marche about how he put together the sections of the Pennsic dance floor. That floor takes way more stress than I think your tent platform will. :-)
(no subject)
You might ping Filip of the Marche about how he put together the sections of the Pennsic dance floor. That floor takes way more stress than I think your tent platform will. :-)