I checked "Other" for the systems design part - network, encryption, hardware, storage, etc. design.
Beyond that, like it seems most of us, I checked a few - I assumed Development included mostly applications development, while Development DBA included mostly admin-type development (backups, restores, index maintenance, monitoring, scripting out objects, automatic object generation, etc.).
I think one big takeaway is, as always, the terms themselves are subjective - I was surprised not to see Systems DBA on there, personally.
ETA: I assumed "None of the above" are for lurkers, .NET developers, and early stage accidental DBA's that don't consider themselves to have moved into another category yet 🙂