How did trade early africans develop advanced societies?

a.
it introduced them to new religions.

b.
it allowed them to make weapons out of iron.

c.
it made the gold they mined more valuable.

d.
it allowed them to trade natural resources for items they needed.

South central region

Ifound the exercise on the internet. attached is the list mentioned above.in order for a compound to be considered optically active it can't have any axis or plan of symmetry. the molecule  shouldn't also  be superimposable on its mirror image.with such considerations, the compounds that are optically active are: -third compound on the first image is optically active; -second and third compound from the second image are optically actives.