Why didn't the European conquerors use native people captured in war to work the plantations?

The social contact theory states that

All of the following apply to a company’s stockholders except: a. they make all company decisions. b. they are also called shareholders. c. they may sell their stock to others. d. they are entitled to share in company profits .

Which of the following most likely contributed to the outbreak of world war ii? a. embargoes on international trade b. higher tariff rates in european countries c. sanctions imposed by the united states d. global economic depression