The Congress of Vienna was considered a success because it was the first time in history that on a continental scale national representatives came together to formulate treaties, instead of relying mostly on messages from the several capitals. The Congress of Vienna was a conference headed by the monarchs of Austria and it was to provide a long-term peace plan for the superpowers of Europe and to have stability in Europe.
Answer: I'm late but the answer is D. support settlement of U.S. territory gained through the U.S.-Mexican War
Explanation:
In the famous Zimmermann telegram from the foreign office in Germany, he proposed that Germany and Mexico should form and alliance in the event that the United States declare war on Germany, since Mexico would be able to launch a swift attack.