Question

what prompted france to sign a formal alliance with the colonies during the american revolution?
great britains victory at the battle of long island
ben franklins negotiations on behalf of the colonies
the formation of the continental congress
the colonial victory at the battle of saratoga

Explanation:

The American victory at the Battle of Saratoga in 1777 demonstrated to France that the colonies had a real chance of winning their war for independence. This convinced France to formally ally with the colonies to weaken its long - time rival, Britain. Ben Franklin's efforts were important but not the sole trigger. The other options were not the decisive factors for the French alliance.

Answer:

the colonial victory at the Battle of Saratoga