I'll be testing a transfer cable soon as I'm not too confident in a definitive answer, and I didn't know it asks you what you would like to transfer, thanks for that bit of info.
As for using a flash drive, I can't move original xbox game data to an xbox memory card, let alone a flash drive. The only option I get with that data/dlc for say, halo 2 for instance, is to delete it when I go to the options. Xbox Originals is also greyed out when I use the "transfer content" option just to make it clear.