Final answer:
The rate that best represents the relationship between the population of a state and the area of the state is 6 residents per square mile.
Step-by-step explanation:
The rate that best represents the relationship between the population of a state and the area of the state is B) 6 residents per square mile. This rate indicates that for every square mile of the state, there are 6 residents. It shows how densely populated the state is based on the area.