Questions: In 1791, King Louis XVI appealed to the kingdoms of Austria and ?, to assist him in suppressing the revolution in France. A) Britain B) Prussia C) Spain D) the United States

The answer is B) Prussia

Britain was not directly appealed to by King Louis XVI for assistance in suppressing the French Revolution. While Britain was concerned about the revolutionary events in France, it did not form an alliance with Louis XVI for this purpose.

Prussia, along with Austria, was indeed appealed to by King Louis XVI. The two kingdoms formed a coalition to support the French monarchy against the revolutionaries. This led to the Declaration of Pillnitz in 1791, where Austria and Prussia expressed their willingness to intervene in France to restore the monarchy.

Spain was not one of the primary kingdoms appealed to by King Louis XVI in 1791. Although Spain later became involved in the conflicts arising from the French Revolution, it was not part of the initial appeal.

The United States was not involved in European monarchic coalitions against the French Revolution. The U.S. was focused on its own development and maintaining neutrality in European conflicts during this period.