Because B.C stands for Before Christ and A.D means the year of our lord so historians took a turn from the traditional christian time method and made it B.C.E (before common era) and C.E (common Era)
In what I know of D is correct because the Commissioners are the heads of the government.
Because they had coordinated houses that were beautifully designed and had the houses made in graphs
B and D I think you can try it if you want if I’m wrong I’m sorry
