Who built Great Zimbabwe? Indigenous Africans

Ancient Greeks

Ancient Egyptians

Begun during the eleventh century A.D. by Bantu-speaking ancestors of the Shona, Great Zimbabwe was constructed and expanded for more than 300 years in a local style that eschewed rectilinearity for flowing curves.

Explanation:

1."lessen the worth of ."

2."increase the worth of."

3." beyond the worth of."

4."against the worth of ."

a and b because with the other three, they simplify to something else.