They would offer free land to the people who came to the west
Diplomacy is defined as the art of conducting relations with other countries, including negotiating alliances, treaties and trade agreements. The largest diplomatic organization in the world are the United Nations with it's headquarters in New York City. Diplomacy usually is referenced to international relations.
C. Less Food Crops were being grown.
My conclusion, given the paragraph given, is that the Belgians likely made the choice given rubbers value to plant rubber trees instead of food wherever practicable.
B. I believe it was Puerto Rico. I just did an essay on Puerto Rico last semester.