Which of the Following Was the Most Likely Driving Factor

Which of the following was the most likely driving factor behind the formation and maintenance of chiefdoms in the Chumash culture?

A) the need to organize small villages into larger groups to resist Spanish attempts to subdue the tribes
B) organizational challenges related to the planting, irrigation, and harvesting of many food crops
C) organizational challenges related to the construction, maintenance, and use of large plank canoes
D) the persistent threat of attack from neighboring tribes searching for additional resources