Answer:
The correct answer is the option A: The Preamble.
Step-by-step explanation:
The Preamble to the United States Constitution is a brief introductory statement of the Constitution's fundamental purposes, bases and principles that lead the nation towards its objectives. It is the evidence of what the Founding Father believed and tried to achieved as well.
The main purposes of The Preamble are the search of liberty, justice, the common defence and more in order to obtain a more perfect Union.