What is Mexico's chief products

Among Mexico's major products and exports are oil (Mexico has a huge oil industry, controlled by the state-owned PEMEX, Petroleos Mexicanos) vehicles, electronics, and other machines, such as pumps, medical and technical equipment, etc.

The answers is D, as the Spanish conquered land but did not know that there were people already living in the territory. For which the Spanish made alliances with the Native Americans living there, gave them borders to the land they each owned. Then they made towns to finish settling the land.