Aside from the Growing European Market for Imports from Spanish

Aside from the growing European market for imports from Spanish colonies, a major reason for the increasing harshness of forced labor was primarily the result of

A) the sheer availability of large amounts of free labor.
B) relaxed attitudes about slavery among the criollos.
C) increased native unrest in the more distant islands.
D) Spanish fears that without slavery the natives would be a continued threat to their economic system.
E) the need for hacienda owners to maintain their elegant lifestyle.