The design of MML3's Mega Man Volnutt hadn't changed much between the original two games, and these designs are also not far removed from those. Option "C" is probably the most radical, only because Mega Man isn't wearing metal shorts.
If you have a favorite design, you can quickly and freely vote in on Capcom's MML3 Devroom site, which also includes some insight from the designers, in case you want some extra convincing. Voting closes April 25.