Economics is the study of how society

The economy is the study of how society allocates scarce resources and goods.

economics can be defined as the science that studies "how a society is organized to produce its means of existence that, distributed among its members and consumed by them, allow society to produce them again and so on, thereby providing a constantly renewed form, the material basis for the whole reproduction of society over time ».

letter d is correct.

they both built pyramids.