The correct explanation for why enslaving the Indigenous peoples of the Americas was largely unsuccessful in fulfilling the needs of the plantations is:
European colonizers’ cruelty, as well as the spread of disease, meant that many Indigenous people died. As a result, there were not enough people left for colonizers to enslave.
This reflects the historical context accurately. The arrival of Europeans led to widespread violence and exploitation, and the introduction of diseases such as smallpox devastated Indigenous populations, decimating communities and significantly reducing their numbers. Consequently, this left European colonizers with an insufficient labor force for their plantations, which contributed to the shift toward importing enslaved Africans as a more viable solution to meet labor demands.