The correct answer is D) The alliance provided the Continental Army with the support it needed to take on the British.
The significance of the French signing an alliance with the United States during the American Revolution was that the alliance provided the Continental Army with the support it needed to take on the British.
This alliance was formally called Franco-American Alliance and later Treaty of Alliance, and was signed in 1778. This alliance represented a military agreement in which France would provide the Continental Army the supplies needed to better fight in the Revolutionary War against Britain. The treaty was finally reached after persistent negotiations of General Benjamin Franklin and the victory of the Continental Army in the battle of Saratoga.