Final answer:
Aristotle's function argument concludes that human beings should live rationally in accordance with virtue to achieve eudaimonia, which is a flourishing life. This differs from simply pursuing pleasure, wealth, or knowledge.
Step-by-step explanation:
Aristotle's "function argument" is central to his ethical theory and is meant to explain the purpose of human life. In this argument, concluded in option (c), Aristotle posits that the unique function of human beings is to engage in rational activity in accordance with virtue. This practice leads to eudaimonia, which is not simply a state of happiness but a flourishing and fulfilling life. To Aristotle, virtues are necessary habits or excellences that enable us to live in a way that fulfills our rational nature. Contrary to options (a) and (b), pursuing wealth or maximizing pleasure and minimizing pain is not the purpose of life for Aristotle. Option (d) is inaccurate, as while knowledge is important, it is the cultivation of virtue through rationality that is central to Aristotle's ethics.