I would like the Hexblade subclass, I enjoy that class a lot, but I think A or C is the most likely option. A because it requires the least amount of work, but I think if they actually want to address the problem, then C would be a good way. After all, adding a feat is pretty trivial since it only really tweaks some numbers around. and such. It won't require a lot of in-depth work.
As an aside, I suspect the reason they didn't include pact of the blade in EA is because they had to reckon with the fact you're supposed to be able to turn it into any weapon, so they had to implement a system for that. And knowing Larian, they probably would want to make each weapon look special based on the patron you take.
