Questions Are Based on the Following Image

Questions are based on the following image. Silver mining at Potosí in the Andes, circa 1590
-What is the source of labor depicted in the mining operation image above?

A) Spanish soldiers tried to get rich by mining.
B) Slaves were imported from Africa.
C) The Spanish applied the Incan mit'a to recruit local labor.
D) The Spanish applied the Aztec hacienda system to recruit local labor.