Final answer:
The first paragraph of the passage most likely serves to establish context about the Mississippian culture, including the significance of maize agriculture and mound building to their societal development.
Step-by-step explanation:
The student is inquiring about the primary function of the first paragraph of a passage on the Mississippian culture. Based on the provided information, which details the importance of mound building, agriculture, and chiefdoms, we can determine that the main purpose of the introductory paragraph is likely to establish context about the Mississippian culture and how it was defined by certain key features. This could include mentioning the shift to maize agriculture and the development of chiefdoms with earthen mound building as a central architectural and cultural element.
A major reason for the cultural shift in the Mississippian tradition, as cited in the provided content, was the adoption of maize agriculture (option a). This agricultural revolution had a significant impact on the Mississippian people, leading to large settled agricultural communities and the spread of cultural, architectural, and technological practices, which were integral to the Mississippian tradition and chiefdom organization.