Which of the following statements is true concerning perspectives on migration control and open borders?

a$)$ Both the conventional and open borders approach argue that states have a prima facie duty to maintain open borders.

b$)$ The open borders approach argues that states have a right to control their borders and regulate immigration in accordance with national priorities, while the conventional approach argues that states have a prima facie duty to maintain open borders.

c$)$ Both the conventional and the open borders approach argue that states have a right to control their borders and regulate immigration in accordance with national priorities.