Why did the Framers agree to add a bill of rights to the Constitution after it was ratified?

A. Federalists would not support the U.S. Constitution without the guarantee of a list of rights.
B. Federalists convinced the Anti-Federalists that it would be easier to ratify with a bill of rights.
C. Anti-Federalists convinced the Federalists that it would be harder to ratify with a bill of rights.
D. Anti-Federalists would not support the U.S. Constitution without the guarantee of a list of rights.