Why were state constitutions significant when the u. s. constitution was written?

a.
state constitutions did not guarantee rights, so the authors of the u. s. constitution included a bill of rights.

b.
the people who wrote the state constitutions had learned valuable lessons about writing a constitution.

c.
by using the state constitutions as models, the delegates to the constitutional convention avoided almost all disagreements.

d.
most of the u. s. constitution was directly copied from state constitutions.