If you have a big enough table then B is nice, and also makes it easier when people want seconds etc. If it would make the table crowded though, definitely go C.
We generally have meat and roast potatoes served from a benchtop buffet, then all the other side dishes (veggies, salad, bread etc) on the table.
Do not do A. It will be a nightmare as not everyone will want some of everything and some people will eat more than others etc. Also, by the time you finish dishing all that up there is the potential for food to have gone cold.
It will move a lot faster if everyone can serve themselves and there will be a minimum of fuss.