According to George Washington's Farewell Address, which of these is MOST important to sustaining the United States and will be MOST frequently attacked by enemies?

In George Washington's Farewell Address, he emphasized the importance of national unity and cautioned against the divisive nature of political parties. He saw the unity of the states as essential to sustaining the nation and believed it would be frequently attacked by both internal and external pressures. Therefore, the response that is MOST important to sustaining the United States and will be MOST frequently attacked by enemies is:

B: unity of the states.