The Olmec civilization’s economy was based on the sharing of resources. trade with other civilizations. the use of currency to buy goods. available resources and bartering.

I believe it's bartering. or letter D

Explanation:

The Olmec used wood and rubber from trees as well as mineral resources to make goods. Minerals are things like stone that come from the earth. People also bartered or traded resources and goods. They did not use money like we do today. Examples of things the Olmec made and bartered with include clay pottery,  They also made clay sculptures and masks.  STARIGHT FROM NOTES

i think the answer is c, rivers.

explanation:

sometimes, borders fall along natural boundaries like rivers or mountain ranges. for example, the boundary between france and spain follows the crest of the pyrenees mountains. for part of its length, the boundary between the united states and mexico follows a river called the rio grande. the borders of four countries divide africa’s lake chad: niger, chad, cameroon, and nigeria.

a standing committee

explanation: