Question refers to the excerpt below.

"all this is related by americo, who adds that they returned to spain and arrived at cadiz with 222 indian captives, where they were, according to him, very joyfully received, and where they sold all the slaves. who will now ask whence they stole and carried off the 200 natives? this, as other things, is passed over in silence by americo. it should be noted here by readers who know something of what belongs to right and natural justice, that although these natives are without faith, yet those with whom americo went had neither just cause nor right to make war on the natives of those islands and to carry them off as slaves, without having received any injury from them, nor the slightest offence what report, or what love would be spread about and sown among the natives, touching those christians, when they left them wounded and desolate? "

—from the letters of amerigo vespucci and other documents illustrative of his career
translated by clements r. markham

the practice described in the vespucci excerpt most clearly foreshadows which of the following?

the unintentional transfer of devastating diseases to the "new world"

the encomienda system that justified near slavery with a requirement for religious conversion

a system called columbian exchange in which native people converted to earn their total freedom

a caste system that marginalized people of mixed european and indian ancestry