The olmec are considered the "mother culture" of mesoamerica. where are they located?

a. along the coast of the gulf of mexico
b. near the columbia river in washington
c. extending along the andes mountain range
d. in the desert west

The correct answer is A, along the coast of the Gulf of Mexico.

Although the Olmec culture had a diffusion that reached most of Mesoamerica, one of the regions where the clearest evidences of the presence of this culture have been found is the southern part of the Coastal Plain of the Gulf of Mexico, included between the Papaloapan and Grijalva rivers, which corresponds to the northern half of the Isthmus of Tehuantepec. Currently, this zone corresponds to the southeast of the state of Veracruz and the west of Tabasco. It is an area of a warm and very humid climate, weather conditions that probably also possessed in the pre-Columbian antiquity in that place.

i think it is a system for harvesting crops more easily

i really really really really really really dont know