G is flexible and covered with plastic, but it is not that flexible that it would increase usability that much. The plastic is likely to deteriorate, and I am not sure how resistant to tampering it would be. (update, Oct 11, it is broken already) B looks likely to jab a passing pedestrian in the crotch, and its painted finish is already peeling. A is way too low to the ground and I think it is likely to trip the unwary.
This is my favorite. It is sturdy, sleek looking, and if placed parallel to pedestrian flow, would not present much of a tripping hazard. From Ian Mahaffy and Maarten De Greeve
More on the competition from the Gothamist
nycityracks - finally-the-finalists
nyc.gov/html/dot/html/bicyclists/bikerack
