Personally, I like dress C.
A is too busy, and would probably over-power someone who is petite--you said you were 5'2", correct?
I'm apparently in the minority, but I don't like B. I feel like it's cheap looking. Maybe it's just because the front looks wrinkled in the picture on DB's website.
Still, only you know what looks best on you. I'm not hugely fond of any of them myself--I think plain wedding gowns look better than sequenced ones. However, that's only because I don't think I could pull-off a really flashy dress.
The girl should wear the dress, not the other way around" sort of thing.