Answer:
D) indentured servitude
Step-by-step explanation:
This question can be answered by ruling out the other answers:
It cannot be A, as slavery is forced, unpaid labour with the labourer considered the property of another, and in the question, it is implied that the poor people are making a choice to participate in this scheme and that they are not considered the possessions of the wealthy.
It cannot be B, as servants must be paid, and the labourers would not be, initially.
It cannot be C, as there is no mention of where the people would be working in the question.
This leaves only D (indentured servitude), which makes sense, as an indentured servant is one who works under a contract for another to pay off a debt, generally in the context described in the question.