What agricultural technique did the Maya use? raised roads
suspension bridges
slash-and-burn farming
artificial islands

Slash-and-burn farming.

Explanation:

All relevant data indicate that the Maya were a classic agricultural civilization. The main products they produced were corn, pumpkin, beans, and chili. Yet when historians point to the downfall of that great civilization, they point out several factors. One of the assumptions is that the agricultural system was too weak to satisfy all the civilization's desires. The number of Maya grew over time, and there was no progress in the farming system.

the answer is a) to be able to obey them.

the term is einsatzgruppen