This is a subjective question, but in general, the Founders believed that uneducated people should not be allowed to have a say in the movement of the country, and many people today agree.
C Mississippian peoples cultivated corn on Mississippi Valley floodplains and created pottery and immense earthworks
The native populations living along the Mississippi Valley used clay from the floodplains to create potter and the ground provided good soil for corn production. What they are most known for are the earthworks or mounds that they built for burial and artistic works to represent their gods. Cahokia was a large mound site near current day St. Louis and demonstrates the skill and size of these mounds.
B for sure if not that then A
The growing of corn enabled the native Americans to have a much more reliable food source that was produced in large quantities and they also had reserves for bad times. This allowed the populations to grow significantly, and also larger cities to be built and developed. It also contributed that the people in this part of the world to have more time to focus on other things, like sciences, astronomy, architecture, instead of just living day by day and be in a constant search of food.