The correct answer is A: "Solidify the Union by making the U.S. a stronger nation."
During the time between the establishment of the Thirteen Colonies and the time after the American Revolution pre-dating the War of 1812, most Americans felt a much stronger allegiance towards their colony/state than the one they felt towards the United States as a nation. For revolutionaries and other fellow Americans, the term "my country" could either refer to the colony/state they had been born and lived in or to the United States.
As the Americans managed to fight the British in spite of the initial heavy losses and the destruction of the capital, Washington, D.C., a new sense of country/nation emerged and Americans from different states would be able to see beyond their local priorities and begin to understand and accept plans, projects and priorities intended to benefit the nation as a whole.