Why was the support of new york and virginia important even after nine states had ratified the constitution?

Their failure to ratify would reduce the new union by two large, populated, wealthy states, and would geographically splinter it. The Federalists prevailed, however, and Virginia and New York narrowly approved the Constitution. When a bill of rights was proposed in Congress in 1789, North Carolina ratified the Constitution. Finally, Rhode Island, which had rejected the Constitution in March 1788 by popular referendum, called a ratifying convention in 1790 as specified by the Constitutional Convention. Faced with threatened treatment as a foreign government, it ratified the Constitution by the narrowest margin (two votes) on May 29, 1790.

The answer is c. good luck : )