Law directs our acts in relation to our ultimate end. And human beings, if they were indeed ordered only to an end that did not surpass the proportion of their natural ability, would not, regarding reason, need to have any direction superior to natural law and human laws derived from the natural law. But because human beings are ordered to the end of eternal blessedness, which surpasses their proportional natural human capacity as I have maintained before, God needed to law down a law superior to the natural law and human laws to direct human beings to their end.

How is human reason related to the natural law, according to the text?
a) Human reason is independent of the natural law
b) Human reason follows the natural law
c) Human reason opposes the natural law
d) Human reason is irrelevant to the natural law