The correct answer is C. Benjamin Franklin
Step-by-step explanation:
In 1778 as part of the American Revolutionary War, an alliance was formed between France and the United States or colonies. This alliance implied France provided supplies to continue the war and achieve independence. One of the most important figures in this process was Benjamin Franklin as he was the one that negotiated the alliance and therefore made possible the support of France, this can be explained as Franklin worked as an ambassador of the United States in France from 1776 to 1785. Thus, the colonial leader that helped form a Franco-American alliance in 1778 is Benjamin Franklin.