What was one of the most consequential mistakes the Robert E. Lee made at Gettysburg? A:Joining forces with other officers
B:Advancing to Cemetery Hill
C:Ordering Pickett's Charge
D:Retreating after day 2

i believe it is b, since in making that advance it costed them to become vulnerable during the war which was one of there biggest mistakes

Explanation:

for many centuries there were important factors which the economies of the muslim empires developed increasingly. they applied economic procedures in production, investment, finance, taxation and property. they used to tax certain goods (for example: harvest), they charged interest on money lent, they signed contracts with merchants; they relied on a common currency, and they used checks as well as promissory notes. with the money collected by means of taxation, the government provided the needy with an income. in addition, trading networks covered huge distances, so far regions started to have contact and exchange goods. this trade network covered areas of asia, africa and europe.