Why did plantation owners train enslaved workers in specialized fields? check all that apply. to require workers to pay for training to workers earn better wages to have needed skilled workers on site to rent workers to others to prepare workers for the job market

They did that in order: 
-to have needed skilled workers on site (so those workers could maintain the correct operational steps in the plantation)
-to rent workers to others (due to the specialized skill, plantation owners could provide the service according to the workers' skill)
-to prepare workers for the job market (For the slave owners' selling benefit)