Final answer:
Virginia colonists turned to slave labor due to the shortage of indentured servants. Indentured servitude did not meet the labor needs of tobacco planters, and the high death rates among Europeans led to the use of African slaves instead.
Step-by-step explanation:
The part of the reason why Virginia colonists decided to use slave labor was that there were not enough indentured servants to meet the high demand. Initially, indentured servants were used as a labor force in Virginia, but there were limitations to this system. The hot climate and diseases in the region led to high death rates among Europeans, and indentured servitude did not satisfy the labor needs of tobacco planters. As a result, colonists turned to African slaves, as they believed Africans were physically better suited to hard labor. This marked the shift from indentured servitude to slavery in the colony.