Answer:
a. An upper legislative chamber based on the principle of equal state representation and lower legislative chamber based on the principle of proportional representation.
c. Three distinct and separate (legislative, executive, and judicial) branches of government.
d. Democratic control by the people over the central government.
Step-by-step explanation:
The American constitution was created to solve problems that the articles of the confederation were not capable of. Although the constitution had some similarities with the articles of the confederation, there were elements that were presented only by it and that were essential for the construction of the government that we know today.
First, the constitution created a central government that had democratic power over the states and population control. Second, it created a higher legislative chamber based on the principle of equal representation of the State and a lower legislative chamber based on the principle of proportional representation.
The constitution also separated the government into three branches (legislative, executive and judicial).