The Preamble's first three words tell us that the authority of the
Constitution comes from
a. The Constitution Convention
b. Member of Congress
c. State Legislatures
d. Ordinary Americans

D. Ordinary Americans.

Explanation:

The Preamble's first three words tell us that the authority of the Constitution comes from ordinary Americans.

The first three words in the United States Constitution are, "We The People." While this may seem very simple, it means a lot to America and shows how important American citizens are for the impact of the country.

"We The People" shows how the United States government commits to serve the American people and do everything in their best interest for them. It is essentially the backbone of the country, creating something by the people and for the people.  

boundary is what it refers to hope this

explanation:

determination