After searching I discovered your question is multiple choice. The answer choices are as follows:
A.By using the state constitutions as models, the delegates to the Constitutional Convention avoided almost all disagreements.
B.Most of the U.S. Constitution was directly copied from state constitutions.
C. State constitutions did not guarantee rights, so the authors of the U.S. Constitution included a bill of rights.
D. The people who wrote the state constitutions had learned valuable lessons about writing a constitution.
The correct choice is A.