Answer:
In the distribution of scarce resources, caste systems rely on ascribed statuses and class systems rely on achieved statuses. (letter D)
Explanation:
Class systems present a social hierarchy that results from a person's achievements, that is, through their effort. For instance, you can be born poor but end up wealthy by gaining knowledge that will lead you to better job opportunities. Therefore, this type of system has social mobility. It also allows for interactions between classes.
On the other hand, a caste systems is more rigid. Its statuses depend on what you already possess at birth, on what is ascribed to you. That is, your gender, race, wealth, etc. are all determined by your family, by what you are born with. This type of system does not allow for much mobility.